Inverse Functions HSC 1996: 7b (1 Viewer)

[Sleight_of_Hand]

Consider the function f(x) = (1/4)[ (x-1)^2 + 7]

The largest domain containing the value x = 3 is x >= 1

Therefore, let a be a real number not in the domain. Find f^-1 ( f(a) )

i.e. find the inverse function of f(a) where a < 1



Ok so i tried to solve this, and got the result: a-2

However the answer is 2-a

Why?

 

[Pwnage101]

 

[Sleight_of_Hand]

thanks

 

[nikkifc]

There's another elegant geometrical approach to this problem (which uses symmetry). I might post it later.

 

[adomad]

There's another elegant geometrical approach to this problem (which uses symmetry). I might post it later.

 

[nikkifc]

Yep that was it. It's so much easier than the above algebraic approach