Prove the following identities, where the angles involved are acute angles for which the expressions are defined.
$\frac{\cos A}{1+\sin A}+\frac{1+\sin A}{\cos A}=2 \sec A$
Prove the following identities, where the angles involved are acute angles for which the expressions are defined.
$\frac{\cos A}{1+\sin A}+\frac{1+\sin A}{\cos A}=2 \sec A$
$\frac{\cos A}{1+\sin A}+\frac{1+\sin A}{\cos A}=2 \sec A$
$L.H.S.\,=\frac{\cos A}{1+\sin A}+\frac{1+\sin A}{\cos A}$
$=\frac{\cos ^{2} A+(1+\sin A)^{2}}{(1+\sin A)(\cos A)}$
$=\frac{\cos ^{2} A+1+\sin ^{2} A+2 \sin A}{(1+\sin A)(\cos A)}$
$=\frac{\sin ^{2} A+\cos ^{2} A+1+2 \sin A}{(1+\sin A)(\cos A)}$
$=\frac{1+1+2 \sin A}{(1+\sin A)(\cos A)}=\frac{2+2 \sin A}{(1+\sin A)(\cos A)}$
$=\frac{2(1+\sin A)}{(1+\sin A)(\cos A)}=\frac{2}{\cos A}=2 \sec A$
$=R . H . S .$
Similar Questions
In $\triangle$ $OPQ$, right-angled at $P$, $OP =7\, cm$ and $OQ - PQ =1\, cm$ (see $Fig.$). Determine the values of $\sin Q$ and $\cos Q$.
In $\triangle$ $OPQ$, right-angled at $P$, $OP =7\, cm$ and $OQ - PQ =1\, cm$ (see $Fig.$). Determine the values of $\sin Q$ and $\cos Q$.
Prove the following identities, where the angles involved are acute angles for which the expressions are defined.
$\sqrt{\frac{1+\sin A }{1-\sin A }}=\sec A +\tan A$
Prove the following identities, where the angles involved are acute angles for which the expressions are defined.
$\sqrt{\frac{1+\sin A }{1-\sin A }}=\sec A +\tan A$
Evaluate:
$\frac{\sin 18^{\circ}}{\cos 72^{\circ}}$
Evaluate:
$\frac{\sin 18^{\circ}}{\cos 72^{\circ}}$
$\frac{2 \tan 30^{\circ}}{1+\tan ^{2} 30^{\circ}}=$
$\frac{2 \tan 30^{\circ}}{1+\tan ^{2} 30^{\circ}}=$
Evaluate:
$\frac{\tan 26^{\circ}}{\cot 64^{\circ}}$
Evaluate:
$\frac{\tan 26^{\circ}}{\cot 64^{\circ}}$