# Inverse of Linear Function

• May 14th 2010, 07:40 PM
vvc531
Inverse of Linear Function
If f is a linear function such that f(x+2)-f(x)=6
find the value of f^-1(x+2)-f^-1(x)
• May 14th 2010, 08:00 PM
Quote:

Originally Posted by vvc531
If f is a linear function such that f(x+2)-f(x)=6
find the value of f^-1(x+2)-f^-1(x)

hi

let the function be ax+b

f(x+2)-f(x)=6

ax+2a+b-ax-b=6

2a=6 , a=3

so f(x)=3x-b

Now , find their inverses ,

$f^{-1}(x)=\frac{x-b}{3}$

$f^{-1}(x+2)=\frac{x+2-b}{3}$

then do as the question asks .
• May 15th 2010, 02:23 AM
vvc531
I have already done the steps shown. Can someone show me the answer so I can verity whether mine is correct?
• May 15th 2010, 03:10 PM
mr fantastic
Quote:

Originally Posted by vvc531
I have already done the steps shown. Can someone show me the answer so I can verity whether mine is correct?

If you had said this in the first place then:

1. You would have got the help you needed a lot faster.

2. People wouldn't be wasting their time - unpaid - posting things you have already done.

If you want verification of an answer, say what answer you got.