[tex]f(x)=3x^2+1\\
g(x)=2x+2\\\\
y=2x+2\\
2x=y-2\\
x=\dfrac{1}{2}y-1\\
g^{-1}(x)=\dfrac{1}{2}x-1\\\\
(f\cdot g)(x)=f(x)\cdot g(x)\\\\
(f\cdot g^{-1})(2)=(3\cdot2^2+1)(2\cdot2+2)\\
(f\cdot g^{-1})(2)=(12+1)\cdot6\\
(f\cdot g^{-1})(2)=13\cdot6\\
(f\cdot g^{-1})(2)=78
[/tex]