If f is a function such that f(2)=4, which of the following could be f^-1, the inverse function of f?

Question

ganeshie8 · Answer

`which of the following...`

where are they ?

anonymous · Answer

(a) = (sqrtx) +2
(b) x^2
(c) (1/2)x
(d)2^x

ganeshie8 · Answer

f(2) = 4
when u feed in 2, it is spitting out 4

so the inverse function must do the exact opposite : 
when u feed in 4, it must spit out 2

ganeshie8 · Answer

plugin x=4 in each of the options and see which one evaluates to 2

anonymous · Answer

c?

ganeshie8 · Answer

Yep!

anonymous · Answer

So for these types of questions, all we have to do is just plug them in?

ganeshie8 · Answer

that will do, i don't see any other way

anonymous · Answer

Great, thank you!

ganeshie8 · Answer

yw! just remember that if (a, b) is a point on f(x), then (b, a) will be a point on its inverse function.