I've included my responses to part A and part B that are referenced in the question. Please be sure to use power reduction formulas and other necessary trig identities on Part B to establish whether part A and B are consistent with each other.

iii. Use the power reduction formulas and other necessary trig identities on your answer to Part B to establish if the responses from Parts A and B are consistent with each other. Parts A Sin (4x) - 8 5 in(2x) +12x 32 Parts B X - 7 Sin 2x+ 32 Sin CHX ) + C