Question

Help please

Answer 1

@phi

Answer 2

everywhere you see x in the "definition" of G(x), put in F(x)
then replace the F(x) with the "definition" they give for F(x)

Answer 3

C?

Answer 4

in the first choice, you start with
G(x) = x+4

can you replace "x" with F(x) ?
what do you get? i.e. erase the x, and write F(x) instead.

Answer 5

G(x)=fx+4

Answer 6

almost. don't forget the x on the "left side"
G(f(x)) = f(x) + 4

Answer 7

the next step, is we look at the question and see
f(x) = x^2
that means we replace (on the right side)
f(x) with x^2
i.e. on the right side of the = sign, in
G(f(x))= f(x)+4
erase the f(x) and write x^2 in stead
what do you get ?

Answer 8

Oh okay so it would just be the original equation equals.... right?

Answer 9

G(f(x))=x^2

Answer 10

x^2+4***

Answer 11

oh, good

and that is what they want, so it's the answer

we could do the same with the other choices to show they do not become x^2+4

Answer 12

But where is x^2+4 as an answer

Answer 13

choice D??

Answer 14

we were checking choice A:
F(x)= x^2 and G(x) = x+4

we started with G(x) and replaced x with F(x):
G(F(x)) = F(x)+4
then we replace F(x) with x^2:
G(F(x))= x^2 + 4

and if we read the question, that is what they want.

Answer 15

oh okay so A =)

Answer 16

if we check choice D:
F(x) = x^2 and G(x) = 4
we start with
G(x) = 4
we replace all x's with F(x):
G(F(x)) = 4

we now replace any F(x) (on the right side) with x^2
but there is no F(x)! so we are done:
For choice D we get
G(F(x)) = 4
and that is not what we want.