Question

If f(x) = 4x – 1 and g(x) = x^2 + 2x + 2, what is f(g(x))?

Answer 1

What have you tried? :)

Answer 2

I tried F.O.I.L.ing 4x-1(x^2+2x+2) .

Answer 3

See if this helps:

if \( f(x) = x +2\) and \(g(x)= x^2\) then \(f(g(x)) = x^2+2\)

Answer 4

In your case, it will be something like \( 4(x^2 + 2x + 2)+1 \) now simplify :)

Answer 5

I don't get it. wouldn't it be x^3+2?

Answer 6

No, FOIL has not thing to do with composition.

Answer 7

ohhh I didn't know that.

Answer 8

So is the answer 4x^2+8x+9?

Answer 9

Yes, but I made a lil mistake in sign 4(x^2 + 2x + 2)-1 so that's 4x^2+8x+7

Answer 10

Ohh alright thank you :D

Answer 11

Could you help me with another problem?

Answer 12

if f(x)=x-2/2, then what is f^-1(x)?

Answer 13

Do you know what is inverse function?

Answer 14

and are you sure it's 2/2 ?

Answer 15

Not really... & yeah it's x-2 over 2.

Answer 16

2x+2

Answer 17

But you should read about inverse function in detail. There are some subtle things here.

Answer 18

Thank you & will do :)

Answer 19

Glad to help :)