List of top Mathematics Questions on Trigonometric Identities asked in MET

If \(\cos^{-1}p + \cos^{-1}q + \cos^{-1}r = 3\pi\), then \(p^2 + q^2 + r^2 + 2pqr\) is equal to

If \(\cos^{-1}\frac{x}{2} + \cos^{-1}\frac{y}{3} = \theta\), then \(9x^2 - 12xy\cos\theta + 4y^2\) is equal to