∫(cos 2x − cos 2α)/(cos x − cos α) dx equals:
∫(cos 2x − cos 2α)/(cos x − cos α) dx equals:
- A. 2(sin x + x cos α) + C
- B. sin x + x cos α + C
- C. 2sin x + x cos α + C
- D. cos x + x sin α + C
Answer: A) 2(sin x + x cos α) + C
Explanation: cos 2x = 2cos²x − 1, cos 2α = 2cos²α − 1. Numerator = 2(cos²x − cos²α) = 2(cos x − cos α)(cos x + cos α). Integral = ∫2(cos x + cos α)dx = 2sin x + 2x cos α + C.
0 Answers
Log in to post your own answer or join the discussion.
No comments yet — start the discussion.