Practicing Success
The value of $ sin\left(2 tan^{-1}\frac{1}{3}\right) + cos \left(tan^{-1}2\sqrt{2}\right)$, is |
$\frac{12}{13}$ $\frac{13}{14}$ $\frac{14}{15}$ none of these |
$\frac{14}{15}$ |
$ sin\left(2 tan^{-1}\frac{1}{3}\right) + cos \left(tan^{-1}2\sqrt{2}\right)$ $=sin \left(sin^{-1}\frac{3}{5}\right) + cos \left(cos^{-1}\frac{1}{3}\right) $ $\left[∵ 2 tan^{-1}x = sin^{-1}\frac{2x}{1+x^2}\right]$ $=\frac{3}{5}+\frac{1}{3}=\frac{14}{15}$ |