a) [tex](g\circ f)(2)=g(f(2))=g(-1)=\boxed{5}[/tex]
b) [tex](g \circ f)(0)=g(f(0))=g(1)=\boxed{6}[/tex]
c) [tex](f \circ g)(3)=f(g(3))=f(3)=\boxed{0}[/tex]
d) [tex](f \circ g)(4)=f(g(4))=f(4)=\boxed{1}[/tex]