Evaluate the following integrals involving a combination of algebraic and trigonometric functions.
a. (i) Compute I=∫(3x−4)2cos((3x−4)3)dx.
b. (ii) Using the antiderivative obtained in part (i), determine the exact value of ∫12(3x−4)2cos((3x−4)3)dx. Express your answer without any remaining integrals.