Question Detail
Question
Determine the indefinite integral ∫cos⁴x dx
Correct Answer
Option A is the correct answer.
Detailed Explanation
Using the reduction formula for ∫cosⁿx dx repeatedly on cos⁴x gives ¼cos³x sinx + 3/8 cosx sinx + 3x/8 + C.
Hint
Apply the cosine reduction formula twice, stepping down from n=4 to n=2 to n=0.