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Integer arithmetic |
2002-12-05 |
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From A student:
Would you please help me with a question?
I am just learning about integers. Can you show me in a way I might understand....My teacher can tell me what is required to do the math, but it just doesn't make sence to me.
(+4) - (-3) =+7
Why is the answer not +1
Answered by Diane Hanson. |
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A rope trick |
2002-12-05 |
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From Jerry:
My name is Jerry and I am a math teacher at the secondary school level in the greater Toronto area. I posed the following problem to my enriched grade 10 math class that I found in the book called "Mathematics and the Imagination" by William Kastner. According to the author, it is posible for two people linked to each other with two ropes around their hands, to separate themselves without letting go of the rope. The students had lots of fun trying to accomplish this problem using skipping ropes from the Phys Ed department, but with no success.
Answered by Penny Nom. |
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Factoring a cubic |
2002-12-05 |
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From Dorota:
I got a problem with factorise the expression
2x3+11x2-5x-50.
Answered by Penny Nom. |
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Which is the better buy? |
2002-12-04 |
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From Lynda:
my question is the big can held 18 ouces and cost $2.52.The small can held only 12 ounces and cost $1.08. Find both unit prices. which can was better buy?
Answered by Penny Nom. |
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65,125 |
2002-12-04 |
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From Brittany:
I am a three-digit number.When you reverse my digits,a larger number is formed.the product of me and the new number is 65,125.What number am I.
Answered by Chris Fisher and Claude Tardif. |
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The dimensions of a box |
2002-12-03 |
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From Paula:
My son, who is in secondary school, needs to make a box with the inside dimensions of 1.25 cubic feet. It's supposed to be more in the shape of a rectangle than a square. I would like to know the equation to use to find the inside dimensions of a box if I know how many cubic feet (or inches) I need the inside to be.
Answered by Penny Nom. |
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A Normal probability problem |
2002-12-03 |
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From A student:
The height of married men is approximately normal with mean 70 and standard deviation 3. The height of married women is approximately normal with mean 65 and standard deviation 2.5. What is the probability that a random married woman is taller than a random married man?
Answered by Andrei Volodin. |
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A geometric sequence |
2002-12-02 |
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From Wanda:
the fifth term of a geometric sequence is 5/16. the common ratio is 1/2. What are the first four terms of the sequence.
Answered by Penny Nom. |
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Tiffany plays first board for her middle school chess team |
2002-12-02 |
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From Patty:
Tiffany plays first board for her middle school chess team. Since she joined the team last year, she has won 27 of 51 tournament games. That's a winning percentage of about 53%. If Tiffany went on a winning streak, how many games would she need to win in a row to raise her winning percentage to 60% Use variables and equations to communicate the method you've used to solve the problem.
Answered by Penny Nom. |
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How do you estimate the equation of a parabola? |
2002-12-01 |
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From Audrey:
How do you estimate the equation of a parabola? I have a project where a must find parabolas in magazines and then estimate their equation.
Answered by Penny Nom. |
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Trigonometry |
2002-12-01 |
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From Lance:
My question is:
FIND ALL SOLUTIONS cosx=1-sin(x/2) if x[0,2pi)
ALSO:
Given cscx=-5/4 and cot>0, find csc(x/2) and cot(x/2)
Answered by Penny Nom. |
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Trigonometry problems |
2002-12-01 |
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From Chiara:
- Find tan 35pi/4
- Graph y = cos2x - 2sinx
Answered by Penny Nom. |
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The height of a triangle |
2002-11-29 |
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From Dean:
Could you please tell me the formular for me to calculate the height of a triangle. I have the angles and side lengths. I am trying to calculate the height of an isosceles triangle, does this make a difference from a normal triangle or is the formular the same.
Answered by Penny Nom. |
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Constructing a tangent to two circles |
2002-11-28 |
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From Tom:
I have two circles, different sizes a known distance from each other. We know the radii of the circles. How do I construct a line that is tangent to both circles relative to the segment that connects the centers of both circles?
Answered by Chris Fisher and Penny Nom. |
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x + y=80 and x + z=100 |
2002-11-28 |
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From PJ:
x + y=80
x + z=100 can you solve for x, y or z?
Answered by Penny Nom. |
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