‹ Back to the paper
Solve the following.
Solve: sin⁻¹(cos(sin⁻¹ x)) = π/3
Solve: $\sin^{-1}(\cos(\sin^{-1} x)) = \frac{\pi}{3}$
Answer
Answer
$\sin^{-1}(\cos(\sin^{-1}x)) = \frac{\pi}{3}$
$\cos(\sin^{-1}x) = \sin\frac{\pi}{3} = \frac{\sqrt{3}}{2}$
Let $\sin^{-1}x = \theta$; then $\cos\theta = \sqrt{1-x^2} = \frac{\sqrt{3}}{2}$
$1 - x^2 = \frac{3}{4}$, so $x^2 = \frac{1}{4}$
Hence $x = \pm\frac{1}{2}$.
Final answer: $x = \pm\frac{1}{2}$