Question

If f(X)= 5-2x, find f^(-1)(3). The book answer is 1, how did they get that?

Answer 1

I'll have a go:

let x= 5-2y

2y = 5-x

y = (5-x)/2

So f(x)^-1 = (5-x)/2

f(3)^-1 = (5-3)/2

=2/2 = 1

EZ

Before you go can you tell me what the recommended notation is for inverting functions in your text? I always use y=x but you may have something different.

Answer 2

I use y=x as well. I hope that answers your question.
BTW thanks so much for helping me!