Sarkari RiseLogin
NDA 2026 · PYQ · Trigonometry / Maxima · easy

If A and B are acute angles such that 2A + 2B = π, then what is the maximum value of sinA·sinB?

  1. A.1/2✓ Correct
  2. B.1/4
  3. C.√3/4
  4. D.1

Explanation

Given A + B = π/2, so B = π/2 - A, meaning sinB = cosA. Then sinA·sinB = sinA·cosA = (1/2)sin(2A). Maximum value of sin(2A) is 1, so maximum of sinA·sinB = 1/2.
💡 Practice unlimited NDA PYQs + AI-tracked progress on each topic. Sign up free →

Want more NDA practice?

Free daily 10-Q quiz · adaptive mocks · 4,000+ verified PYQs · AI doubt solver in Hindi + English

Sign up freeMore Trigonometry / Maxima practice