# Thread: inverse of function

1. ## inverse of function

i know inverse of inverse of function is the function itself can yu please give me the proof

2. Originally Posted by prasum
i know inverse of inverse of function is the function itself can yu please give me the proof
Why don't you give us your proof?
We will be glad to reply once you show some effort.

3. Isn't it defined as such (over the appropriate domain)?

4. i have supposed y=mx+c then found its inverse then i found the inverse of this again but i think i am wrong

5. Originally Posted by prasum
i have supposed y=mx+c then found its inverse then i found the inverse of this again but i think i am wrong
Every linear function has an inverse.
Swap the x with the y and solve for y.

6. how to do proof

7. Originally Posted by prasum
how to do proof
Proof of what?
Look, this is your problem.
You should show some of your own effort.
Do not make demands of us. That is not the way we work.

8. y=mx+c sox=y-c/m swapping x and y we get y=(x-c)/m agin doing the same process we get
y=mx+c so inverse of inverse function is the function itself

9. Originally Posted by prasum
y=mx+c sox=y-c/m swapping x and y we get y=(x-c)/m agin doing the same process we get
y=mx+c so inverse of inverse function is the function itself
Your basic algebra skills are in need of help.
If $\displaystyle x=my+c$ then $\displaystyle y=\frac{x-c}{m}$.