Question

I need help with this function

Answer 1

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