# Inverse function of f^-1

## Homework Statement

a)The function f is defined by y=f(x) = 3ln 4x 0.01<=x<=1
solve for x in terms of y and hence find the formula for the inverse function of f^-1

b)Write the domain of f^-1

plse help check my answers below...

as above

## The Attempt at a Solution

solve for x in terms of y
My Ans :x= 1/4*e^(y/3)
and hence find the formula for the inverse function of f^-1

gabbagabbahey
Homework Helper
Gold Member

wikipedia said:
wiki

Let $f$ be a function whose domain is the set $X$, and whose range is the set $Y$. Then, if it exists, the inverse of $f$ is the function $f^{-1}$ with domain $Y$ and range $X$, defined by the following rule:

$$\text{If }f(x) = y\text{, then }f^{-1}(y) = x\text{.}$$

Does this help?

P.S. Please don't post double threads. Someone was already helping you with this problem in the other thread. If you didn't understand their attempt at helping you, you should have just said so instead of posting the same question in anew thread.

iam sorry new to the forum.....

is the answer for part b) -9.656<=x<=4.159 ??

gabbagabbahey
Homework Helper
Gold Member

is the answer for part b) -9.656<=x<=4.159 ??

Looks good to me