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A problem with logarithms 2019-08-23
From Iriogbe:
Find the value : if log3 (a-6) =2b and log2 (a-7) =3b
Answered by Penny Nom.
4^x=2^x+6 2019-04-05
From Olivia:
How do you find the (b,n) if the solution of the equation 4^x=2^x+6 can be expressed at logb(n) where b and n are both prime numbers?
Answered by Penny Nom.
4444^4444 2017-12-10
From Sashi:
4444 to power of 4444=?
Please share the result with simplification.

Answered by Penny Nom.
Find two values of x satisfying f(x)=1 where f(x)=sin(ln(x)) 2016-01-21
From Ruth:
I'm trying to find two values of x satisfying f(x)=1 where f(x)=sin(ln(x))
Answered by Penny Nom.
Manipulating an expression using logarithms 2015-05-18
From Katie:
Solve x=At^be^-ct for b in terms of c.
The e is Euler's number, not a letter or random placeholder.
v I've tried 2 methods on my calculator, and I am unsure as to why they give me different answers, and which one is correct.
For some reason, when placing a multiplication sign in between the A and the first t, I get a completely different answer. Why is this?
Also, which is the right answer for the question I have?
Thank you!
Katie :)

Answered by Penny Nom.
How do we use logarithms in our daily life 2014-06-01
From ss:
how do we use logarithms in our dailylife
Answered by Penny Nom.
The inverse of y = 5^x 2014-03-07
From Melody:
how do you find the inverse of y = 5^x
Answered by Penny Nom.
Evaluate log3 14 2013-11-17
From Tash:
Use the Change of Base Formula and a calculator to evaluate the logarithm, correct to six decimal places. Use either natural or common logarithms.

log3 14

Answered by Penny Nom.
4=(1+.08)^x 2013-06-15
From Samantha:
I can't seem to understand how to solve for x when it is in power form, here is the equation:


Answered by Penny Nom.
The exponential form of log8=P 2012-04-25
From Kristina:
what is the exponential form of log8=P
Answered by Penny Nom.
A log equation in exponential form 2011-11-11
From Sarah:
Express the equation in Exponential form

log2 to the 16th power=4

Answered by Penny Nom.
Uses of logarithms 2011-11-09
From BEA:
what is the use of logarithmic functions in real life or daily life?
Answered by Penny Nom.
An equation involving logarithms 2010-09-27
From mindy:
I am trying to find x, the equation is:
log_2(log x + 2 (log x)^(1/2) + 1) - 2 log_4((log x)^(1/2) + 1) = 1

Thank you very much for your time. =)

Answered by Harley Weston.
Log[f(x)] 2010-03-08
From sourabh:
What is the number of solutions of the equation 9 x 2 - 18 x + 5 = 0 for x, such that the expression log10[(x+1)(x+2)] exists?
Answered by Harley Weston.
541.39(1 + i)^15 = 784.09 2009-10-14
From Fitore:
Hi, I noticed that this question was already posted up, however I was hoping I could solve it without having to use logs. Can you please help me? The equation is: 541.39(1 + i)^15 = 784.09
Answered by Penny Nom.
Exponential form 2009-08-05
From motaz:
Let x = log_2 1/8 Write the exponential form of the equation and solve the equation for x
Answered by Stephen La Rocque.
Log_7 (4X) = Log_14 X 2009-07-08
From Mukulu:
Help me with this question because i tried my level best to get the right answer but i failed Log_7 (4X) = Log_14X
Answered by Stephen La Rocque.
(logx)squared + log (xcubed ) +2 =0 2009-05-19
From michael:
Solve for x: (logx)squared + log (xcubed ) +2 =0
Answered by Penny Nom.
An inequality with logs 2009-03-06
From Indrajit:
(x/10)^(logx - 2)<100..........how to solve this one??
Answered by Stephen La Rocque.
6^x = y 2009-02-12
From Jamie:
Find x: 6^x=y
Answered by Harley Weston.
A log base 2 problem 2008-11-26
From dave:
solve for x

(log base 2 of x) - (log base 2 of (x-2)) = 3

Answered by Penny Nom.
How do you solve "logx^4=4? 2008-11-17
From Scott:
How do you solve "logx^4=4"?
Answered by Penny Nom.
4^x = 2^x + 12 solve for x 2008-10-02
From Dave:
4^x = 2^x + 12 solve for x.
Answered by Harley Weston.
What is the derivative of (2^sinx)/(logbase4(2x+1))? 2008-09-16
From Jesse:
What is the derivative of (2^sinx)/(logbase4(2x+1))
Answered by Harley Weston.
2^x = 1,000,000 2008-09-06
From Peter:
How do I solve for "x" in the following equation: "2 to the power of x = 1,000,000" ?
Answered by Penny Nom.
Solve e^x + e^(x+1) = 250 2008-08-25
From Laura:
"solve this equation correct to three decimals"
e^x + e^x+1= 250

Answered by Penny Nom.
Write log_2 (1/8) = -3 in exponential form 2008-06-27
From Jaime:
how do you write log2 (1/8) = -3 in exponential form?

the 1/8 is a fraction and the 2 is a base of 2

Answered by Penny Nom.
limit x->0 (logx-log(x-1)) 2008-05-22
From kritica:
lt x->0 (logx-log(x-1))
Answered by Harley Weston.
Which is larger, 727464^512693 or 624610^518548? 2008-05-18
From Yahweh:
Lets say I have two very large numbers in the form of a^b: 727464^512693 and 624610^518548

I want to calculate which number is larger, but its unreasonable to type these numbers into a spreadsheet to get an answer right away. How could I determine the larger or the two numbers efficiently?

Answered by Stephen La Rocque.
The inverse of a function 2008-05-03
From keith:
please help me find the inverse of this function:

h(t) = 2 + 4 ln(1-5t)

Answered by Stephen La Rocque.
log2x+log(x+4)=1 2008-04-12
From ryan:
solve the equation for x, log2x+log(x+4)=1
Answered by Penny Nom.
log(0.81) 2007-06-28
From Ade:
If log 3 = 0.477 . The answer of log 0.81
Answered by Harley Weston.
A problem involving logs 2006-11-26
From Beth:
any help would be appreciated on how to solve without using the change of base formula for logarithms in the solution and check of the solution!!!

log256 (x) + log16 (x) + log4 (x) + log 2 (x) = 7/4

Answered by Stephen La Rocque and Penny Nom.
How many digits are in the number 2^64? 2006-06-14
From Trang:
How many digits are in the number 264?
Answered by Stephen La Rocque.
Differentiation, powers and logs 2006-01-06
From Claudia:

Question: how do I find the derivative of

x* ln(x+(e^2))^2



Answered by Penny Nom.
Some logarithm problems 2005-01-27
From Jo:
Given ln x=7.1; ln y=8.2, Find ln(x^3y^7)
Answered by Penny Nom.
Logs 2004-02-29
From Sandy:
find X

my book uses prop 7 to rewrite as logb4raised3/2-logb8raised2/3+logb2=logbx; then writes logb8-logb4+logb2=logbx how did it get here?

Answered by Claude Tardif.
A problem with logs 2004-02-22
From Caitlyn:
problem: ln x + ln (x-2) = 1

I can solve this on the calculator, but the book wants 1+ [(sqroot)1+e]. How can I get the e?

Answered by Penny Nom.
Logarithms 2004-02-01
From A student:
Where did the word logarithmic come from? Where/whom did it originate?
Answered by Harley Weston.
Domain of a function 2003-10-14
From Karim:
Find the Domain of the Function
H(x) = Log3 (4x + 7)-10
H(x) = log base 3 times 4X plus 7 minus 10
i am having problem solving these kinds of problems.

Answered by Penny Nom.
Solve x = y^z for z 2003-06-28
From Nathan:
If x = y^z is there a way to solve for z, if x and y are given, without guessing or already knowing the answer?

ie: 64 = 2^z
6 is the obvious value for z. Is there a way I could solve for this variable using a formula, which would also apply when more complex values were substituted for x and y?

Answered by Penny Nom.
1996^1999 and 1999^1996 2001-07-29
From Rajesh:
what is greater 19991997 or 19971999?
Answered by Chris Fisher.
Where will we use this in the real world? 2000-10-11
From Jane Ann Musgrove:
As a teacher of mathematics, I am always asked "Where will we use this in the real world?". I am seeking ideas/sites via the internet where students can find answers to this type of question. Can you help me?

To be more specific, right now I am interested in finding careers where the employees would use the concepts of "Radicals", "Matrices", and "Logarithms". This information will be used by students to make presentations to the class on their findings from internet searches.

Answered by Harley Weston.
Two calculus problems 2000-05-01
From Kaushal Shah:
How Do WE Integrate the following Functions,
  1. Integral xtanx dx
  2. How was natural base "e" discovered and why e=2.7.......

Answered by Claude Tardif.
Logs 2000-04-12
From Jessica:
Write as a single log 3ln x - 2ln(y+e) + 5ln(x-12) - 4ln y
Answered by Harley Weston.
Characteristic of a logarithm 2000-03-14
From Andrew Strauss:
What is the characteristic of log base 18 of 1980 ?
Answered by Harley Weston.
Logarithms 2000-01-18
From Jennifer:

Hi I have a test tomorrow and I was wondering if you could help me with these two problems.

  1. Explain how to express y in terms of x if log3y=4log3(2X)

  2. The LN key on your scientific calculator is not working, but the ex and LOG keys are. Write directions for calculating a natural logarithm using the ex and LOG keys. Explain why these directions will get you the right answer.

Answered by Harley Weston.
Three algebra problems 1999-12-28
From Stephanie Branton:
  1. If P represents the product of all prime numbers less than 1000, what is the value of the unit's digit of P?

  2. Do any real numbers a and b exist such that: ln(a+b)=ln a + ln b? if so, what are they?

  3. Define a function by: f(x)=1/1-x where x is not equal to 0,1. what is f(f(f(a)))?

Answered by Harley Weston.
Logarithms 1999-12-16
From Pierre:
Can you please answer those three question

  1. inverse or the exponential function.

    logx 81 = 4,
    x expo4 = 81,
    x = +or- 4square root 81,
    x = +or- 3
    s.s = {3}
    Why is -3 not acceptable.

  2. .

Answered by Harley Weston.
Two derivatives 1999-11-16
From Gina Renicker:
The derivative of:

y=e(xlnx) and y=x2arctan(x1/2)
Answered by Harley Weston.

Derivatives with logs 1999-10-26
From Kate:
What is the derivative of 5 to the 5x-2 at x equals 0.8?
Answered by Harley Weston.
-log(a) 1999-10-22
From Brenda Miskimmin:
I need to know the mercury concentration in mg/L or ng/L for the following:

-log M (Hg) = 8.5

where mw of Hg=200.59

(it's the negative sign in front of log that confuses me).
Answered by Harley Weston.

Solving using logs 1999-10-11
From Rich Bolton:
Here's my question:


Can you please show me how to do this?
Answered by Penny Nom.

A Series 1999-04-20
From Deepak Shrestha:
Given the sequence an=e^(-n*Ln(n)), does the series converge and why?
Answered by Harley Weston.
Logs 1998-10-21
From Benny:
What does log means? How come we have to use log
Answered by Chris Fisher.
Two Problems 1998-07-28
From James Pulver:
How do you solve these problem? If log abc=16 and log ac=12 , find b. (The logs are log base 10.)
If a and b are real numbers, i^2 = -1 and (a+b)+5i=9+ai what is the value of b?

Answered by Jack LeSage.
A Problem with Logs. 1997-11-26
From Herman:
Given log 24=a, log 25=b and log 26=c, express log 39 in terms of a, b and c.
Answered by Penny Nom.
Natural Logarithm Functions 1997-04-23
From Rickson:
The following two questions are some of my son's homework that he is having trouble with......any advice or assistance would be appreciated.

(eX)5=1000.............the X and 5 are exponents

lnx + ln(x+3) = ln10

In each question the problem is to find x.
Answered by Harley Weston.




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