1.8.4 a. What compositions can you form using the following functions? cos x i. f = x2+y? ii.g 8) = 2a+62 iii. f(t) = 2t iv. g +2 sin y b. Compute these compositions. c. Compute their derivatives, both by using the chain rule and directly from the compositions. 1.8.5 The following "proof" of part 5 of Theorem 1.8.1 is correct as far as it goes, but it is not a complete proof. Why not