The value of $ an ^{2} heta-\left(\frac{1}{\cos heta} imes \sec heta ight)$ is :\

Question

The value of $	an ^{2} 	heta-\left(\frac{1}{\cos 	heta} 	imes \sec 	hetaight)$ is :\

Professor PC Thomas Classes · Answer

(c) $: 	an ^{2} 	heta-\left(\frac{1}{\cos 	heta} 	imes \sec 	hetaight)$\ $=	an ^{2} 	heta-\sec 	heta 	imes \sec 	heta$ $$ \left[\because \frac{1}{\cos 	heta}=\sec 	hetaight] $$ $=	an ^{2} 	heta-\sec ^{2} 	heta=-1$\ $\left[\because \sec ^{2} 	heta-	an ^{2} 	heta=1ight]$\