Question

for f(x)= 1/x^2 and g(x)=x^2. find (fog)(x)

Answer 1

Isn't that just f(g(x))? Let's see what you get. Do what the notation suggests.

Answer 2

i just plug it in?

Answer 3

It's called "substitution", but that's the idea.

Answer 4

oh okay well , would i plug or substitute the x^2 into the other x^2?

Answer 5

\[(fog)(x)=\frac{1}{x^4}\]

Answer 6

@electrokid Nover do that again.

If h(x) = 3x + 2

h(2) = 3(2) + 2
h(\(\sqrt{2}) = 3\sqrt{2} + 2\)
h(frog) = 3(frog) + 2
h(g(x)) = 3(g(x)) = 2

Whatever it is, just substiute it.

Answer 7

okay but for this equation how would i do that if they are both x^2?

Answer 8

The are NOT both \(x^{2}\). They are as they are defined.

\(f(x) = \dfrac{1}{x^{2}}\;and\;g(x) = x^{2}\)

\(f(g(x)) = \dfrac{1}{[g(x)]^{2}} = \dfrac{1}{(x^{2})^{2}} = \dfrac{1}{x^{4}}\)

Whatever it is, just substitute it. No need to overthink it. Just do it!

Answer 9

ohh okay . thanks