The value of $sin^{-1} \left(\frac{8}{17}\right) + sin^{-1} \left(\frac{3}{5}\right)$ is : |
$sin^{-1}\left(\frac{77}{85}\right)$ $cos^{-1}\left(\frac{77}{85}\right)$ $tan^{-1}\left(\frac{77}{85}\right)$ $cot^{-1}\left(\frac{77}{85}\right)$ |
$sin^{-1}\left(\frac{77}{85}\right)$ |
The correct answer is Option (1) → $\sin^{-1}\left(\frac{77}{85}\right)$ $\sin^{-1} \left(\frac{8}{17}\right) + \sin^{-1} \left(\frac{3}{5}\right)=y$ $A=\sin^{-1}\frac{8}{17}$, $B=\sin^{-1}\frac{3}{5}$ $\sin A=\frac{8}{17}$, $\sin B=\frac{3}{5}$ Using $\cos θ=\sqrt{1-\sin^2θ}$ $\cos A=\frac{15}{17}$, $\cos B=\frac{4}{5}$ $A+B=\sin^{-1}(\sin(A+B))$ $=\sin^{-1}(\sin A\cos B+\sin B\cos A)$ $=\sin^{-1}\left(\frac{77}{85}\right)$ |