Thread: Inverse funciton

The function f(x)= ax+b , f-1(x)=8x-3. Find a and b

I would be very happy if you explained how to do it.

Thank you

Originally Posted by Oasis1993

The function f(x)= ax+b , f-1(x)=8x-3. Find a and b

I would be very happy if you explained how to do it.

Thank you

let f(x)= ax+b =y (say)
then ax+b =y


................(1)
but given ................(2)
on comparison eq(1) and (2)

and

Thank you very much!

Just to put in my oar: 8x- 3 says "first multiply x by 8 and then subtract 3".

The "inverse" is the inverse of the original operarations ("divide by 8" rather than "multiply by 8" and "add 3" rather than "subtract 3") done in the opposite order.

So the inverse of "first multiply x by 8 and then subtract 3" is "first add 3 to x and then divide by 8".