Answer:
a) 0; b) 4[tex]x^{2}[/tex]
Step-by-step explanation:
a) To compute f o g (0), first evaluate g(x) for x=0 and then evaluate f for x=g(0).
[tex]f \circ g (0)=f(2 \cdot 0)=f(0)=0^2[/tex]
b) To compute a mathematical expression for f o g do the same but instead of 0 use x,
[tex]f \circ g (x) = f( 2 \cdot x)= (2 \cdot x )^2[/tex]