If , where , then for all is equal to
- (A)
- (B)
- (C)
- (D)✓ Correct
Answer: (D)
Solution
Take the cosine of . The difference formula gives . Moving the first term across and squaring, ; the terms cancel and, after multiplying through by , the expression collapses to .
JEE Main · 2019 · 10 Apr 2019 · Shift 2 · Single correct option