Prove the following identities, where the angles involved are acute angles for which the expressions are defined.

$(\operatorname{cosec} A-\sin A)(\sec A-\cos A)=\frac{1}{\tan A+\cot A}$

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$(\operatorname{cosec} A-\sin A)(\sec A-\cos A)=\frac{1}{\tan A+\cot A}$

$L.H.S.=(\operatorname{cosec} A-\sin A)(\sec A-\cos A)$

$=\left(\frac{1}{\sin A}-\sin A\right)\left(\frac{1}{\cos A}-\cos A\right)$

$=\left(\frac{1-\sin ^{2} A}{\sin A}\right)\left(\frac{1-\cos ^{2} A}{\cos A}\right)$

$=\frac{\left(\cos ^{2} A\right)\left(\sin ^{2} A\right)}{\sin A \cos A}$

$=\sin A \cos A$

$R.H.S=\frac{1}{\tan A+\cot A}$

$=\frac{1}{\frac{\sin A}{\cos A}+\frac{\cos A}{\sin A}}=\frac{1}{\sin ^{2} A+\cos ^{2} A}{\sin A \cos A}$

$=\frac{\sin A \cos A}{\sin ^{2} A+\cos ^{2} A}=\sin A \cos A$

Hence,$L . H . S=R . H . S$

Similar Questions

If $\tan A =\cot B ,$ prove that $A + B =90^{\circ}$

In $\triangle ABC ,$ right-angled at $B , AB =24 \,cm , BC =7 \,cm .$ Determine:

$(i)$ $\sin A, \cos A$

$(ii)$ $\sin C, \cos C$

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:

$\frac{\tan 26^{\circ}}{\cot 64^{\circ}}$

State whether the following are true or false. Justify your answer.

$(i)$ $\cos A$ is the abbreviation used for the cosecant of angle $A$

$(ii)$ cot $A$ is the product of cot and $A$.

$(iii)$ $\sin \theta=\frac{4}{3}$ for some angle $\theta$.