5. (a) Let f: R R be defined by f(x) = x², let g: RR be defined by g(x) = sin x, and let h: R→ R be defined by h(x) = 3√x. Determine formulas for [(hog) of] (x) and [ho (go f)](x). Does this prove that (hog) of = ho (go f) for these particular functions? Explain. (b) Now let A, B, C, and D be sets and let f: A → B, g: B → C, and h: CD. Prove that (hog) of = ho (go f). That is, prove that function composition is an associative operation. BY NC SA