Question 52349
f(x)=x^2+4
g(x)=x-1
(gof)(x) means you substitute the function of f into the function of g where x is.
(gof)(x)=g(f(x))=g(x^2+4)
g(x^2+4)=(x^2+4)-1
        =x^2+4-1
        =x^2+3
(fog)(x) means you substitute the function of g into the function of f where x is.
(fog)(x)=f(g(x))=f(x-1)
f(x-1)=(x-1)^2+4
      =(x^2-2x+1)+4
      =x^2-2x+1+4
      =x^2-2x+5