







Positive and negative values of a function 
20180130 

From Grayson: f(x)=x^6x^4
Interval: ( negative infinity, negative one )
Test Value: negative two
Function Value f(x): positive forty eight
Interval: ( negative one, zero )
Test Value: negative one
Function Value f(x): zero
Interval: ( zero, positive one )
Test Value: positive one
Function Value f(x): zero
Interval: ( positive one, positive infinity )
Test Value: positive two
Function Value f(x): positive forty eight
What is the sign of f(x) for each Interval? Answered by Penny Nom. 





A five digit number 
20161012 

From Massa: Explain why any four digit number is less than any five digit number? Answered by Penny Nom. 





The modulus of a complex number 
20160729 

From Cheyenne: There's a question on my Summer Assignment I cant figure out. Here it is:
Find the absolute Value of the complex number. 5i
Please help? Answered by Penny Nom. 





Maximizing the area of a two lot region 
20160403 

From yousef: A man wishes to enclose two separate lots with 300m of fencing. One lot is a square and the other a rectangle whose length is twice its width. Find the dimensions of each lot if the total area is to be a minimum. Answered by Penny Nom. 





A place value drawing 
20160224 

From Kristin: Make a place value drawing of a number that has
double the number of tens as ones and three times
the number of thousands as hundreds write the number. Answered by Penny Nom. 





A concrete container 
20151112 

From Karstin: The exterior of a concrete container will be 10 feet by 8 feet by 4 feet tall. The walls and the bottom are 6 inches thick. What will it cost to construct it if concrete is $98.95/cubic yard? Answered by Penny Nom. 





A six digit number 
20140630 

From anupam: hi,
my daughter asking a solution for the below question, kindly help.
Write the smallest 6 digit number wit digits ( 2,4,3,0,5,7).
plz this is an urgent requirement.
regards,
anupam Answered by Penny Nom. 





A table of values 
20140327 

From Marisol: A table value X 0,1,2,3,4,5,6 and Y 3,7,11,15,19,23,27 . what relationship of X to Y is represent by which equation? A . y= 4x. B y =x+3 . C y =4x+3 or . D y =4x3 Answered by Penny Nom. 





$9.50 in coins 
20140115 

From dana: you have $9.50 in coins. it has twice as many nickels as quarters and three times as many dimes as nickels. how many of each coin do you have? Answered by Penny Nom. 





What is the value of 2((i)^(1/2))? 
20130722 

From Delilah: What is the value of 2((i)^(1/2)) ?
i.e. absolute value of 2 multiplied by square root of i. Answered by Penny Nom. 





Transposition error 
20121203 

From Carol: What is the correct term for when a child writes 61 instead of 16, or 83 for 38when they switch the place values of a number? Answered by Chris Fisher. 





5<2x+1<1 
20121111 

From Rahul: How does 5<2x+1<1 changes to 1<2x+1<5. What is the rule?
Can we apply absolute value function throughout the first inequality i.e. can we say 5<2x+1<1. But then it becomes 5<2x+1<1 which is impossible because 5 is not less than 1. Answered by Penny Nom. 





Expected value 
20120825 

From melanie: The probabilities are 0.24 , 0.35 , 0.29 , and 0.12 that a speculator will be able to sell a subdivision lot within a year at a profit of P120, 500 , at a profit of P80,000 , at a profit of P40,000 , or at a lost of P60,000 respectively . What is his expected profit ? Answered by Penny Nom. 





Expanded exponential form? 
20120612 

From Ramon: express the numbers 990 614 000 005 in expanded exponential form. Answered by Harley Weston. 





Expected value 
20120224 

From Lara: A life insurance company sells a $250,000 1year term life insurance policy to a 20yearold male for $350. According to the National Vital Statistics Report the probability that the male survives the year is 0.998734. Compute and interpret the expected value of this policy to the insurance company.
I'm very confused on how to do this. I assume x is the profit the insurance company makes in the year of $350 but beyond that I don't know what to do. Thanks. Answered by Penny Nom. 





Rounding 
20111214 

From seth: A decimal number rounded changed to 23.7 after it was rounded.
Give a decimal number that is less than 23.7 and another that is greater than 23.7 that each round to 23.7.
Explain to what place each number was rounded. Answered by Penny Nom. 





I started with Euler's identity and manipulated it 
20111114 

From anonymous: I started with Euler's identity and manipulated it
e^i*pi=1
e^i*pi=(1)^1
e^i*pi=1
e^i*i*pi=(1)^i
e^pi=(1)^i
e^pi=(1)^i
type it in in a calculator and you get e^pi=23.1406926... and
(1)^i=0.0432139183... What did I do wrong? Answered by Robert Dawson. 





Expanded form 
20111012 

From Chris: Write this number in expanded form
4 326 180 501
Thanks!!! Answered by Penny Nom. 





Place value 
20110920 

From Ivana: the digit in the ones place is a hand with out a thumb(4)
2) the digit in the thousands place is 2 less than the digit in the one's place.
(42=
3) the digit in the ten's place is the sum of 2 and 6 (2+6=
4) the digit in the hundreds place is what you get when you get when you subtract 5 from the digit in the ten's place (ten's5=
what is the number? Answered by Penny Nom. 





What does 163,100,000 look written in words? 
20110322 

From Alicia: What does 163,100,000 look written in words? Answered by Penny Nom. 





The greatest value of 5 –  x – 3 
20110116 

From pranav: What is the greatest value of 5 –  x – 3  for any integral value of x.
< br />
PRANAVM Answered by Penny Nom. 





Linear inequalities with absolute values 
20101201 

From ryan: Good day!
We we're given this assignment in algebra concerning linear inequalities with absolute value.
In this number I'm confused how to isolate the absolute value, considering there is a variable in the absolute value and there is a variable in the outside.
2+5 43t+t ≤ 34t Answered by Penny Nom. 





A 35% profit 
20101119 

From Ana: You have a stamp collection and make a 35% profit by selling it on EBay for $2700. Find the original cost of the collection by using the formula:New value × 100 / 100 + percent change = Original value Answered by Stephen La Rocque. 





x+ 3 = x1 
20100921 

From Jack: x+ 3 = x1 Answered by Penny Nom. 





Compound interest 
20100601 

From Kenneth: Hello:
I have a question regarding the following compound interest and future value
calculation.
Year 1 P + rP equals balance after the first year.
Year 2 (P + rP) + r(P + rP) equals balance after the second year.
Year 3 ? equals balance after the third year.
This question is in two parts.
1. What would follow for year three?
2. I know that a pattern will develop. What will it be so that I can determine
the extended pattern for following years ? Answered by Penny Nom. 





Percentage increase 
20100520 

From Rebecca: Question from Rebecca:
In 2008 my land was valued at $84,000. In 2009 my land was revalued at $235,000.00. What is the
percent increase between the two values? I want to be able to express "the
value was increased by x%." Answered by Harley Weston. 





The value of 1 acre 
20100513 

From Rebecca: If 38,121 sq feet equals $19,846.58 at 75% of its current value, what would the value of 1 acre be at 100% of value? Answered by Penny Nom. 





The rejection region 
20100501 

From Mong: In Tests of Hypothesis, what is the decision when the test statistic we compute from the sample information is exactly equal to the critical value? that is, we reject null hypothesis or do not reject it?
Thanks! Answered by Chris Fisher. 





Modelling the roof of a house 
20100323 

From Sandi: This question has been haunting my dreams at night. It states the cross section of the roof of a house is modelled by the function y= 5\12x12+5, where y>0 or y. Now I'm suppose to graph the function. b) Find the slope, height, length of sides, and base of the isosceles triangle. c)Explain what transformation must be applied to the graph of y=x to obtain the graph of y= 5\12x12+5, where y>0 or y=0. 1st I put the equation into my calculator and graphed it. I got 10 for the height. We have had 2 sub teachers this past week. The first one told me the height should be 12 the other one told me 5. So I'm really confused. If I use my 10 units as height and the Pythagorean Theorem I get my sides to be 26 units the base 48 and my slope I calc to be 5/12. Both teachers are pretty sure I'm wrong and they are right but we all have different answers. Please help put this problem to rest so I can rest soundly at night. Thank you for your time. Answered by Penny Nom. 





34 
20100210 

From Nick: I have another question. This is how i solved it and i know its suppose to be a negative.
z= 34 Answered by Penny Nom. 





Excluded values 
20091114 

From Janie: I have to State the excluded values for this equation and then solve, but not sure how to do this. Here is the problem
(x+6)/x+3=(3)/(x+3)+2 Answered by Harley Weston. 





f(x) = 3x  6 + 1 
20091026 

From kelsey: find the coordinates of the vertex f(x)= l3x6l + 1 Answered by Penny Nom. 





The worth of a word 
20090923 

From Kaliegh: If each letter of the alphabet is worth one cent more than the previous
letter and the letter "a" is worth one cent. What words would have a
worth equal to 1 cent,10 cents,50 cents,87 cents 64 cents and $1.00? Answered by Robert Dawson. 





y=2x+1 and y=2x1 
20090828 

From MARICELA: Need help of how to work this problems
y=2x+1 and y=2x1
First of all what is the difference?
Second I think is easy just to work with the X y with the line in the middle
but how do you get the numbers for each side. Answered by Penny Nom. 





1/(x+1) <1 
20090516 

From Nazrul: What is the solution of absolute value of (1/(x+1))<1? Please explain. Answered by Stephen La Rocque. 





Expected value 
20090411 

From jp: you pay $.50 and pick a fourdigit number. The state chooses a fourdigit number at random and pays you $2500.00 if your number i chosen. What are the expected winnings from a $.50 Pick 4 wager? Answered by Stephen La Rocque and Harley Weston. 





y = x  4 
20090128 

From tiana: how do you find where to plot Y in a problem that states y=x 4? Answered by Robert Dawson and Penny Nom. 





Saving for his daughter's education 
20090115 

From George: To save for his daughter’s university education at the end of each month Mr McLean sets aside £50 in a savings scheme paying 10% p.a. compounded monthly. He begins saving when his daughter is 3 years old. How much will he have saved by the time his daughter is 18? Answered by Harley Weston. 





The table of values for y=3x10 
20090109 

From Jade: How can I know the value of x for y=3x10 in this table of values pls. include the deatails
if x=2 y=16
if x=3 y=1
but how if y=2 what is x Answered by Penny Nom. 





Separating variables 
20081104 

From Terry: by separating variables solve the initial value problem
(x+1)y' + y = 0 y(0) = 1 Answered by Harley Weston. 





Absolute value 
20081104 

From Shane: What is the absolute value of 4 Answered by Penny Nom. 





What number has 5 hundreds and 12 tens? 
20081021 

From kellee: What number has 5 hundreds and 12 tens?
I would say the number is 620. But, my daughter thinks that is wrong. Answered by Harley Weston. 





What is the exact value of pi? 
20080927 

From mahesh: what is the exact value of pi.
22/7 is accurate value of pi, if not then how can i find out the exact pi value. Answered by Harley Weston. 





Extraneous solutions 
20080925 

From crystal: /6x+7/=5x+2 Answered by Penny Nom. 





The minimum value of f(x)=maximum{x,x+1,2x} 
20080921 

From Saurabh: The minimum value of the function defined by f(x)=maximum{x,x+1,2x} ? Answered by Penny Nom. 





The Intermediate Value Theorem 
20080916 

From A.: When dealing with the intermediate value theorem you have the function x^2. It bounces on the axis so you can't tell if lies on the interval [a,b]. So is the ivt proven false or does the ivt not tell you all the roots for sure. Answered by Harley Weston. 





Hundreds, tens, and units digits 
20080905 

From Cynthia: write an expression for the value of a threedigit number whos hundreds, tens, and units digits are x, y, and z, respectively Answered by Penny Nom. 





Units digit 
20080702 

From seemachauhan: How to find unit digit of various numbers and what are unit digits? Answered by Penny Nom. 





Excluded values 
20080509 

From Andrew: Finding Excluded Values
j+1

2j6 Answered by Penny Nom. 





Excluded values 
20080416 

From Jenny: Give the excluded values for the fraction m+5/mn+3m
m=
n= Answered by Penny Nom. 





f(x) =ax^blnx 
20080413 

From charles: supposef(x) =ax^blnx is a real valued function. Determine exact values(not decimal approximations) fro nonzero constants a and b so that the function f has a critical point at x=e^3 and a maximum value of 1/2e Answered by Harley Weston. 





Expected value and standard deviation 
20080319 

From Patrick: Heres a question i cant figure out:
a small airline company has only three flights per day. The number of
delayed flights per day is regarded as a random variable, and I'm
supposed to calculate the expected
value and standard deviation of the number of delays.
the probability distribution looks like:
No. of Delays: 0 1 2 3
Prob. of delay: 05. 0.3 .1 .1 Answered by Harley Weston. 





Absolute value 
20080124 

From Cara: Give the absolute value of this equation.
{3 + 1}  {5  7}
note: the brackets are the absolute value lines. Answered by Penny Nom. 





Which expression gives the greatest value? 
20071218 

From Jordan: 'Look at these expressions'
n2, 2n, n(squared), n over 2, and 2 over n (sorry I can't type the expressions out)
A) Which expression gives the greatest value when n is between 1 and 2?
B) Which expression gives the greatest value when n is between 0 and 1?
c) Which expression gives the greatest value when n is negative?
As you can see, this IS ONE question split in to three parts lol!
Can you tell me how I go about tackling this question? I lost marks on the test because of not
understanding the question. Answered by Stephen La Rocque. 





pvalues and tdistributions 
20071113 

From Don: I have a ttest statistic of 1.28 and a degree of freedom of 6.
I know the pvalue is .248 I cannot figure out how to calculate that value.
I have used software to get it but I want to know how to calculate it using
the tdistribution table. Answered by Harley Weston. 





Place value 
20071027 

From eric: True or False:
In the number 378, there are 3 hundreds, 7 tens, and 8 ones. Answered by Penny Nom. 





The largest number you can add ... 
20071026 

From Dryden: What is meant by asking what is the greatest number you can add to that number without having to regroup in any place? Answered by Penny Nom. 





The average rate of change of a function 
20071011 

From vern: Find the average rate of change of the function over the given interval. Compare this average rate of change with the instantaneous rates of change at the endpoints of the interval. f(X)=sinX for the inverval [0,pi/6]? Answered by Harley Weston. 





I have a 6 digits 
20070928 

From Kim: I have a 6 digits. My hundredthousands digit is 1 less that my ones digit, 8 more than my thousands digit, twice my tens digit, and 4 times my hundreds digit. My tenthousands digit is 0. What number am I? Answered by Stephen La Rocque. 





Tens and ones 
20070916 

From julia: My son has come home with a math question "what i know about 10s and 1s" we're totally stumped any information you can provide would be greatly appreciated Answered by Harley Weston. 





A place value chart 
20070912 

From glenwood: draw a million chart then place the following numbers in the proper place.
one hundred and nine million, seven hundred and twentythree Answered by Penny Nom. 





What number am I? 
20070811 

From Belinda: What number am I? My millions digit is 4. My billions digit is two time =
my millions digit. My hundred thousands digit is two more than my =
millions digit and three more than my ones digit. My ten millions digit =
is one less than my ones digit. My other digits are zero. Write my =
short word form. Answered by Penny Nom. 





A statistics example 
20070802 

From Claudia: A particular employee arrives to work some time between 8:00 am  8:30 am. Based on past experience the Company has determined that the employee is equally likely to arrive at any time between 8:00 am  8:30 am.
On average, what time does the employee arrive?
What is the standard deviation of the time at which the employee arrives?
Find the probability that the employee arrives exactly at 8:12 am?
Find the probability that the employee arrives between 8:20 am  8:25 am? Answered by Har. 





sinx and cosx 
20070625 

From Mac: Can anyone tell me whether sinx and cosx is differentiable at x=0 ?
As far as i know, cos(x) and sin(x) is differentiable at all x. Answered by Penny Nom and Stephen La Rocque. 





Normal distribution 
20070524 

From Paula: Consider a data set that is normally distributed.
The mean of the data set is equal to 10,000.
a.) Suppose that, for this data set, 10,625 has a
"zvalue" = 2.5. Solve for the standard deviation of
the data set.
b.) Solve for the "zvalue" of 9,900. Answered by Penny Nom. 





Is the point on a cone called a vertex? 
20070509 

From Felicia: Does a cone have a vertice? My teacher says that a vertice can only be
made if two or more edges join up at an angle, so what do you call a point on a cone? Answered by Walter Whiteley. 





Continuity of y = x 
20070502 

From moulipriya: Is the curve y =  x  continuous everywhere? Answered by Penny Nom. 





Expected value 
20070330 

From Katrina: A term life insurance policy will pay a beneficiary a certain sum of money upon the
death of the policy holder. These policies have premiums that must be paid annually. Suppose a
life insurance company sells a $250,000 oneyear term life insurance policy to a 20yearold male
for $350. According to the National Vital Statistics Report, Vol. 47, No. 28, the probability the
male will survive the year is 0.99865. Compute the expected value of this policy to the insurance
company. Does the company expect to make money at this rate? Answered by Penny Nom. 





Write the interval in absolute value notation 
20070320 

From Timothy: 1. Write interval in absolute value notation
i) xE[0,9]
ii) xE[2,20] Answered by Penny Nom. 





Place value, coins and money 
20061212 

From Emily: I was wondering what the best way would be to teach place value using coins and money. I have used base ten blocks already and am looking for a way to integrate money, perhaps on a place value chart and perhaps using decimals. Answered by Diane Hanson. 





The absolute value of imaginary and complex numbers 
20061211 

From Keith: i don't get how to find the absolute value of imaginary and complex numbers here is an examples from the text book the answers are given but they don't show the work so i can follow along just show me the work please and explain how it is done
problem 3+4i Answered by Stephen La Rocque and Penny Nom. 





What is the expected number of ripe and ready to eat watermelons 
20061129 

From James: An agricultural cooperative claims 95 percent of the watermelons shipped out are ripe and ready to eat. If 20 watermelons are shipped out , what is the probability that the number of watermelon that are ripe and ready to is (i) exactly 14 (ii) more than 18 (iii) of the 20 watermelons that are shipped what is the expected number of ripe and ready to eat watermelons Answered by Penny Nom. 





y = x  10 
20061103 

From Pam: what is the process for finding the vertex point for an equation such as this, y= x  10. Answered by Penny Nom. 





Place value 
20061012 

From Sue: We have extended the place value chart out 14 places and want to know what comes after hundred trillions? Answered by Stephen La Rocque. 





Excluded values 
20060605 

From Mike:
i need to find the excluded values of:
2n^{2}9n+4 / 2n^{2}5n12
Answered by Penny Nom. 





Absolute Value vs. Standard Deviation ? 
20060424 

From Sonia: Why we don't just take the average of the absolute value of difference scores (use the mean deviation) to describe variability instead of calculating the standard deviation? Answered by Claude Tardif. 





A table of values 
20060328 

From Cindy: Create a table of values for each of the following functions: y=5x, y=52, and y=5x. I dont know to do this. Answered by Stephen La Rocque. 





The Mean Value Theorem 
20051222 

From Candace: Verify that the function satisfies the hypotheses of the Mean Value Theorem on the given interval. Find all numbers "c" that satisfy the Mean Value Theorem. 11. f(x)=3x^{2} + 2x +5 [1, 1] Answered by Penny Nom. 





Whats the value of the digit 7 in 756,809? 
20050914 

From Anastasia: Whats the value of the digit 7 in 756,809? Answered by Penny Nom. 





ax+b = cx + d 
20050322 

From Angel:
ax+b = cx + d
how to show sometimes the above has 2 roots, sometimes 1 root and sometimes
no roots. Hopelessly lost on how to start...
Answered by Penny Nom. 





Four and five digit numbers 
20040921 

From Josy:
The question I have now in front of me is....Is a 4digit number always less than a 5digit number?
Hi Josy,
The digits in order are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Thus the largest four digit number is 9999. The smallet 5 digit number is 10000.
Penny
Go to Math Central
Answered by Penny Nom. 





The pvalue 
20040725 

From Kathy: Ms. Lisa Monnin is the budget director for the New Process Company. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information.
At the .10 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the audit staff? What is the pvalue?
Having problems finding the pvalue & unsure of the formula.
Kathy Answered by Penny Nom. 





An ineqlality with absolute values 
20040705 

From Uneeza: abs(x^{2}  4x) > 3 Answered by Claude Tardif. 





Place Value 
20040425 

From Santosh: Q.
Write the Place value of the digits in the following numerals.
1. 5 in 54
2. 3 in 63 Answered by Penny Nom. 





x^2  12x = 8 
20040124 

From Sherre: x^{2}  12x = 8 Answered by Penny Nom. 





Absolute value 
20030923 

From Crystal: I am trying very hard to understand Absolute Value, and I cannot seem to grasp the idea. I do not know why we use it, what the point of it is. I do not know how to use it. I know that it is always positive or zero, and I assume it relates to distance, but how can you use it in equations. Please explain it to me as simply as possible, thank you. Answered by Walter Whiteley. 





The digits in 349 
20030912 

From Franik: in the number 349, which number has the least value, and why? Answered by Penny Nom. 





x+3 = 15x 
20030719 

From Nathan: Without the use of trial and error, is there a way of solving for x where x + 3 = 15x? I know that x = 0.1875, but how do I find whether x + 3 is positive or not if I did not have this information (In other words, how would I solve whether the xvalue was 3 or less, or if it was more than 3)? Answered by Claude Tardif and Penny Nom. 





E(X + Y) and V(X + Y) 
20030710 

From Reuben:
I'm a teacher trying to find a way to make some stats work from first principles. The topic is expectation algebra and it is for the top age level in high school. By using a set of data I can show how the mean is the same as the expected value ie 2,2,3,4,4 is 15 / 5 = 3 also, 2x0.4+3x0.2+4x0.4=3. I can also show this to work for the variance in the same style but using Sum(xmean)^{2}/n and the Var(X) version of squaring x then multiplying by the probability ( all this for random independant samples). Now comes the tricky bit.....when I try to show E(X+Y) = E(X) + E(Y) from setting up two data sets I get it to work only if I add each item from X to each item from Y. However, I can't get it to work for V(X+Y)=V(X) + V(Y) from two sets of data. There must be something missing in my knowledge of how the sets are required to add together or my knowledge of expectation algebra. I am familiar with proofs but still want to show my students that the basic formulae work from groups of data whether done the long way or by use of formulae. Can you help please? Answered by Penny Nom. 





Excluded values 
20030222 

From Josh: Why do you think it is necessary to include the "excluded values" when you write your answers to rational expressions? Answered by Penny Nom. 





Round to hundredths 
20021119 

From Brittany: Can u tell me how to do a problem like this:
35 divded by 4.8= Round to hundreths. Answered by Penny Nom. 





Future value 
20020627 

From Susan: If one were to invest $115 a month for 20 years and expect a 4% annual return, what is the value of this money in 20 years? Answered by Leeanne Boehm. 





Overlapping circles 
20020529 

From Naman: There are two circles, big circle with radius R and small one with radius r. They intersect and overlap in such a way that the common area formed is 1/2 pi r^{ 2} (half the area of the small circle) If r=1, find the Radius of the big circle (R)? Answered by Harley Weston. 





 n + 4  +  3  2n  = 16 
20020524 

From Randall: I don't seem to be able to solve this:  n + 4  +  3  2n  = 16 Answered by Penny Nom. 





Linear regression 
20020116 

From Murray: If you have a set of coordinates (x[1],y[1]),(x[2],y[2]),...,(x[n],y[n]),find the value of m and b for which SIGMA[from 1 to m=n]AbsoluteValue(y[m]m*x[m]b) is at its absolute minimum. Answered by Harley Weston. 





What is a group of three numbers called in a large number? 
20020115 

From Laurie: What is a group of three numbers called in a large number? My son has this question on his 4th grade worksheet. I've taught middle school math for 7 years and nver heard of it. Answered by Paul Betts. 





Absolute Value 
20011014 

From Susan: I am a homebound teacher, and my nineth grade algebra I student is having trouble understanding absolute value. Please send me an idea about how to best help her. She may be out of the classroom the entire year. Answered by Chris Fisher. 





A linear inequality 
20010917 

From Eric: How can I solve x + y + x  y< =6? Answered by Penny Nom. 





The Mean Value Theorem 
20010723 

From Corrie: I need to find if the mean value theorem exists. and if so, find all values c guaranteed by the theorem. f(x) = x^{2}25 on the interval [10,0] Answered by Harley Weston. 





Expected value 
20010424 

From Cindy: A game consists of rolling a single fair die. If a number great than 4 is rolled you win the number of dollars showing on the die. If any other number is rolled, you receive $1.00. What is the expected value of this game? Answered by Andrei Volodin. 





The domain of the derivative 
20010222 

From Wayne: I know that the domain of f'(x) is a subset of the domain of f(x). Is it necessarily true that the subset will have at most one less element than the domain of the original function? Answered by Harley Wesston. 





Place value chart 
20010111 

From Charles: Can you send me a pictorial example of a place value chart? Answered by Harley Weston. 





How many tens are in 400? 
20001107 

From A student: How many tens are in 400? Answered by Penny Nom. 





Expected number 
20001102 

From James: 1)There are 40,25,50 students in the traditional,reformed,and reformed traditional Calculas sections taught by three teachers. On one fine day the three sections congregate together to watch the NOVA video tape on Fermat's Last Theorem. a) A student is randomly selected from he crowed of students.What is the expected number of students in the same section of this student? ****this question which i did not have any idea to do as follow for the part b b) If one of the three teachers is selected at random, what is the expected number of students taught by is teacher? Answered by Harley Weston. 





The smaller of a and b 
20000914 

From Jenna: For any two real numbers, a and b, give a mathematical expression in terms of a and b that will yield the smaller of the two numbers. Your expression should work regardless of whether a>b, a Answered by Penny Nom. 





7     77 
20000913 

From Peter: Does anyone know how to solve the following: 7 _ _ _ _ 77 ? I have to find the missing values. Answered by Chris Fisher and Walter Whiteley. 





Two geometry problems 
20000909 

From Becky: What are all the real values of x that are solutions for the inequality [x2] < 6? ( it's less than or equal to) What is the distance between the points with (x,y) coordinates (3,2) and (3,1)? Answered by Peny Nom. 





Solving an equation 
20000826 

From Patrick: My question is how would u do a problem like this.......... [2x37] =15?....u have to solve it for absolute value equations....???? Answered by Harley Weston. 





PreCalculus 
20000809 

From Angela: Use absolute values to define the interval or pair of intervals on the real line.
<  ]    [ >
18 19 20 21 22 23 24 25 26
A car is moving at the rate of 50 miles per hour, and the diameter of its wheels is 2.5 feet. a) Find the number of revolutions per minute that the wheels are rotating. b) Find the angular speed of the wheels in radians per minute. Answered by Harley Weston. 





An expected value 
20000424 

From Carl Pride: Suppose that in a statistics class of size 23, each student has a probability of passing of 73 percent. sample: What is the expected number of students who will pass?? Answered by Harley Weston. 





Taxicab geometry 
20000116 

From Jack: Im doing an investigation entitled 'taxicab geometry', ive attempted it and have done most of the practical part of it. But i cant seem to see the equation behind it all. please guide me in the right direction. They provide a regular grid with regular horizontal and vertical lines. The lines are roads and the actual squares are blocks of hoouses/ buildings. In taxicab geometry the distance between place A & B is worked out by adding together the horizontal and vertical distances. each square is counted as i unit. Part 1 (I've done this) A taxix cab firm is based at A. the posistion B is 7 units away from A. investigate all the posistions of B at 7 units. investigate for different distances. . . . Answered by Penny Nom. 





Absolute value 
19991229 

From Alex Waller: What are some practical applications for absolute value? Answered by Harley Weston. 





Advanced Calculus 
19991207 

From Kay: Hi, my name is Kay. Please helpthese problems are driving me crazzzzy!!!! Your help would be greatly appreciated!  Let a,b be contained in R, a
 .
. . Answered by Claude Tardif. 





Inequalities and absolute values 
19991207 

From Austin Cline: Solve for x: The absolute value of x1 is less than or equal to the absolute value of x2 Answered by Harley Weston. 





62x<4 
19991020 

From Tchilco: Solve 62x<4 Answered by Harley Weston. 





Instant Winner 
19990407 

From FSSTAN: The probabilities of being an "instant winner" of $25 or $50 in a lottery are 1/600 and 1/1200, respectively. The mathematical expectation of being an "instant winner" of $25 or $50 is? Answered by Jack LeSage and Penny Nom. 





Finding Excluded Values 
19990401 

From Lorraine Le Cam: The question asks me to find the value of the variable that must be excluded in each rational expressionion. The operation is: a ______ a  2 How do I work this out? Answered by Harley Weston. 





Grade 4 curriculum 
19990209 

From John: My daughter is in grade 4 and her math teacher has asked her to write out the number 1 to 10,000. She is currently at 4567 and is sick of it. When I complained that this was not a usefull exercise she said that the Ministry of Education curriculum requires this and gave a photocopy of the page. It states: "read and write whole number to 10,000 in standard, expanded, and written forms (eg., 9367=9000+300+60+7 = nine thousand three hundred sixtyseven). Has the teacher interpreted this the wrong way? Thanks John PS. Do you have a web address for Ontario Math and Science Teachers organization? Answered by Jack LeSage. 





Absolute value of i 
19990106 

From Wayne Bagley: I would like to know what is the absolute value of i. I need an answer suitable for the secondary level. Answered by Harley Weston. 





Place Value 
19990105 

From Reg: I work in a Section 27 classroom with various grades. I am looking for assistance on how to deliver a lesson on place value:decimal numbers keeping in mind that they need to see it (visual) to comprehend. I am looking for grade 46 level. Answered by Jack LeSage. 





Two Questions 
19971028 

From Melissa Kelley: I would appreciate any help you could give me.  Why isn't 1 a prime number?
 How can the absolute value of a number be negative?
Answered by Penny Nom. 





A Limit Problem 
19970916 

From Robert Reny: what is the limit, as x approaches 0, of 3x/2x[x]? [] means absolute value. Answered by Harley Weston. 





Billions and more! 
19970915 

From Mahabir B. Gupta: I would like to know how you americans write the number 1 billion. Do you say "One thousand million"..can you answer by giving me examples? 1,000,000> 1 million 1,000,000,000>1 billion Why is it that in spanish it is different? Answered by Penny Nom. 





Thousands, millions, billions and trillions 
19960822 

From Blaine: What are the names of the periods in groups of numbers like 123,456,789. I need to know the names of them for school. I already know the first ones: units thousands millions billions trillions. Answered by Penny Nom and Diane Hanson. 

