$\tan ^{-1} \frac{3}{4} + \tan ^{-1} \frac{3}{5} - \tan ^{-1} \frac{8}{19} = $

જો $\operatorname{Tan}^{-1}\left[\frac{1}{1+1(2)}\right]+\operatorname{Tan}^{-1}\left[\frac{1}{1+(2)(3)}\right]+\operatorname{Tan}^{-1}\left[\frac{1}{1+(3)(4)}\right]+\cdots+\operatorname{Tan}^{-1}\left[\frac{1}{1+n(n+1)}\right]=\operatorname{Tan}^{-1} \theta$ હોય,તો $\theta=$

સાબિત કરો કે $\cos ^{-1} \frac{4}{5} + \cos ^{-1} \frac{12}{13} = \cos ^{-1} \frac{33}{65}$

જો $\cos ^{-1} \sqrt{p}+\cos ^{-1} \sqrt{1-p}+\cos ^{-1} \sqrt{1-q}=\frac{3 \pi}{4}$ હોય,તો $q$ ની કિંમત શોધો.

જો $\cos^{-1} x + \cos^{-1} y = 2\pi$ હોય,તો $\sin^{-1} x + \sin^{-1} y$ ની કિંમત શોધો.

જો $\sin ^{-1}\left(\frac{3}{5}\right)+\cos ^{-1}\left(\frac{12}{13}\right)=\sin ^{-1} \alpha$ હોય,તો $\alpha=$