Question 1 The integral fx va + 1 da can be computed using a substitution. Select all reasonable substitutions. Ou= Vr+1 Ou=22 Ou=xvr+1 D Question 2 Which of the integrals can be converted to the form J w" dw, where n is a constant, by a substitution? 4x +3 (a) dx ( b ) e-e ( exter) 3 3 dx Vx* + 3x 2x dx (d) sin x (c) J- " dx x2 + 1 X O (a) and (b) O All of them O (b) and (c) O (a), (b), and (c)