Define the functions
f(x)=x2+1,g(x)=4x−3,
where x∈R. Answer the following questions regarding the composite (g∘f)(x).
a. (i) Calculate (g∘f)(2).
b. (ii) Verify whether (g∘f)(−2) is defined and, if so, find its value.
c. (iii) For a general real number k, write a single algebraic expression for (g∘f)(k). Simplify your result.