# math

posted by .

what is inverse of this funtion
f(x)=(1 / 3)^x?

• math -

Three steps to finding the inverse:
1. interchange x and y.
2. solve for y in terms of x.
3. evaluate f-1(f(x)) to verify that it gives x as the result.

0. y=(1/3)^x
1. x=(1/3)^y
2. log(x)=ylog(1/3)
=> y=log(x)/log(1/3)=-log(x)/log(3)
or
f-1(x)=-log(x)/log(3)
3.
y(f(x))
=y((1/3)^x)
=-log((1/3)^x)/(log(3)
=-xlog(1/3)/log(3)
=x OK

• math -

THANKS ALOT... I GET IT NOW!!!!!!

• math :) -

You're welcome!

## Similar Questions

1. ### math

Could you show me step by step how to find the inverse of this problem: log with base of 2 (x+1) Thanks! It is not clear what the problem is. You are given a function of x. Let's calli it y. Are you trying to come up with an equation …
2. ### Inverse of log function

Find the inverse of f(x) = log(2+x) - 4 the base is "a" Call f(x) y y = loga(2+x) -4 y+4 = loga(2+x) a^(y+4) = 2 + x x = a^(y+4) - 2 drwls, you have merely solved the equation for x. The question was to find the "inverse", so the actual …
3. ### chemistry

Please, can someone help? Evaluate log 1. This is my work up until I have gotten stuck: log 1 1=10^x I can't find a common base for 1 and 10^x. Wow, my apologies, this is algebra, not chemistry. but actually I think they use it in
4. ### Calculus

Find the inverse of each relation: y = (0.5)^(x+2) and y = 3log base 2 (x-3) + 2 For the first one I got y=log base 0.5 (x+2)...but the answer in the back of the textbook says that it is not x+2, but x-2. Can someone tell me why it …
5. ### Review of Logs

I can't seem to get the answer to this; the answer key says log(base 8)6 Write as a single logarithm log(base 8)42log(base 8)3 - log(base 8) 6 I'm hoping the key is wrong :) Thank you for your help!
6. ### Math

these are some problems i do not get any help is appreciated. These are copied exactly from the worksheet so i don't think i wrote anything wrong. Please explain it for me and could i get the answer thanks (: Log7 x= ½ log7 36 (log …
7. ### Algebra 2

-Explain the difference between log base b (mn) and ( log base b of m)(log base b of n). Are they equivalent?
8. ### Algebra 2

I am trying to find the inverse of these functions. Can someone please check my answers and tell me how to do number 2?
9. ### Advanced Functions/ Precalculus Log

1. Evaluate 4^(log base4 64) + 10^(log100) 2. Write 1+log(base2)x^3 as a single logarithm 3. Write log(base b)√(x^3 y z^6) 4. Solve log(base 2)x-log(base 2)6=log(base 2)5+2log(base 2)3 5. Solve 3^(2x) = 9(81^x) 6. Solve 3^(2x)=7^(3x-1). …
10. ### Econ math/logarithms

If log with base b (2)=0.39 and log with base b (3)=0.61 evaluate the following. log with base b (8). Simplify your answer. How to start?

More Similar Questions