Question

Let f(x) = x - 2 and g(x) = x2 - 7x - 9. Find f(g(-1)).

-21

-3

3

21

Answer 1

So we need first find what g(-1) equals.

\[\large g(x) = x^2 - 7x - 9\]
g(-1) simply means plugging in -1 for every 'x' you see there

\[\large g(-1) = (-1)^2 - 7(-1) - 9\]

Tell me what that comes out to

Answer 2

You can also take the approach of finding f(g(x)) first:

f(g(x)) = g(x) - 2
= x^2 - 7x - 9 - 2
= x^2 - 7x - 11

Then finding f(g(-1)) from there.

Answer 3

Okey hold on..

Answer 4

I got -3

Answer 5

That is correct!

Answer 6

Thankyou!