Question

Help?
Fill in the Blank Suppose f and g are inverses and f(3) = −9. Then g(−9) =?
A 3
B 3i
C –21
D 27

Answer 1

If they're inverses then they should equal the same thing

Answer 2

so C?

Answer 3

Hm, no.. here let's make a function: f(x)=-3x

Answer 4

if you plug in 3: f(3)=-9
So now plug in -9 into the inverse: y=-3x
x=-3y
(-1/3)x=y
f(-9)=(-1/3)(-9)
f(-9)=3

Answer 5

A

Answer 6

Oh okay. Makes sense. Thanks!

Answer 7

You are very welcome