x2 Evaluate (x + 4)3 dx in the following steps. (a) Set up a Trigonometric Substitution with an appropriate right triangle and relation between x and the reference angle 0. Transform the above integral into [sin 6 sin tan de. (b) Using cos20+ sin 0 = 1, verify the following trigonometric identity: sin tan 0 sec 0 + cos 0 = (c) Using the results in parts (a) and (b), plus the given formula sheet, evaluate x2 (x + 4)3 dx.