If $\sin x=-\frac{3}{5}$, where $\pi

Question

If $\sin x=-\frac{3}{5}$, where $\pi < x < \frac{3 \pi}{2}$, then $80\left(	an ^2 x-\cos xight)$ is equal to

Aicharya · Accepted Answer

$\begin{aligned} & \sin x=\frac{-3}{5}, \pi < x < \frac{3 \pi}{2} \ & 	an x=\frac{3}{4} \cos x=-\frac{4}{5} \ & 80\left(	an ^2 x-\cos xight) \ & =80\left(\frac{9}{16}+\frac{4}{5}ight)=45+64=109\end{aligned}$

If $\sin x=-\frac{3}{5}$, where $\pi < x < \frac{3 \pi}{2}$, then $80\left(\tan ^2 x-\cos x\right)$ is equal…

Solution