What is (f*g)(x)?
F(x)=x^4-9
g(x)=x^3+9
(f*g)(x)=?
(f * g) (x) means
f(x) * g(x) =
[ x^4 - 9 ] [ x^3 + 9 ] =
x^4 * x^3 - 9*x^3 + 9*x^4 -9*9 =
x^7 + 9x^4 - 9x^3 - 81
