What is (f•g)( x)?

(f•g)(x) --> f(g(x))
Basically, where there is an x, replace it with g(x), in this case x²+2

f(x)=x³-4x+2

f(x²+2)=(x²+2)³-4(x²+2)+2
           =x⁶+6x⁴+12x²+8-4x²-8+2
           =x⁶+6x⁴+8x²+2