$\sin \left(\cos ^{-1}\left(-\frac{1}{7}\right)+\sin ^{-1}\left(-\frac{1}{7}\right)\right) = $ . . . . . . .

$\tan \left[ \cos^{-1} \frac{4}{5} + \tan^{-1} \frac{2}{3} \right] =$

જો $(\tan^{-1} x)^2 + (\cot^{-1} x)^2 = \frac{5\pi^2}{8}$ હોય,તો $x$ =

જો $\alpha > \beta > \gamma > 0$ હોય,તો પદાવલિ $\cot ^{-1}\left\{\beta+\frac{(1+\beta^2)}{(\alpha-\beta)}\right\}+\cot ^{-1}\left\{\gamma+\frac{(1+\gamma^2)}{(\beta-\gamma)}\right\}+\cot ^{-1}\left\{\alpha+\frac{(1+\alpha^2)}{(\gamma-\alpha)}\right\}$ ની કિંમત શું થાય?

$x$ ના મૂલ્યોનો ગણ શોધો જેથી $\tan ^{-1}\left(\frac{x}{x-2}\right)-\tan ^{-1}\left(\frac{x}{2 x-1}\right)=\tan ^{-1}\left(\frac{2}{3}\right)$ થાય.

જો $y = \sin^{-1}\left(\frac{19}{20}x\right) + \cos^{-1}\left(\frac{19}{20}x\right)$ હોય,તો $\frac{dy}{dx} = $