21 wzx/m do: (a) Which trig substitution is correct for this integral? 0 a: = 64 sec(9) O a: = 64 sin(6) O a: = 8tan(9) O a: = 213ec(9) O a: = 64 tan(9) O a: = 8 sin(6) Evaluate the integral: (b) After substituting for a: and simplifying, the integral looks like: f:w Note: to enter 6, type "\\theta". (c) Evaluating this integral you get what function of 0? :]+0 (d) What is this function in terms of ac? 0