Question

(x) = 3x + 9, g(x) = 3x2
Find (fg)(x).

Answer 1

9x^(3) + 27x^(2)
?

Answer 2

prob what u meant is
\[(f \circ g)(x)\]
in that case, means the variable x in the f(x) is now defined as a function of g(x), for simplicity, substitute x in the f(x) by g(x). Thus,
\[f(x)=3x+9\]
then
\[(f∘g)(x)=3[3x^2]+9\]
...since i assume your
\[g(x)=3x^2\]
. First it's very confusing, but if you work on more problem, it becomes more make sense. NOw just challenge yourself with
\[(g∘f)(x)\]

Answer 3

thanks guys

Answer 4

just like San2 stated above

Answer 5

Thanks!

Answer 6

correction:
(fg)x means f(x) times g(x)
this is not a composition of functions

Answer 7

you were actually correct, I am sorry to mislead you......