tan θsec θ−1+tan θsec θ+1 is equal to

Question:

$\frac{\tan \theta}{\sec \theta-1}+\frac{\tan \theta}{\sec \theta+1}$ is equal to

(a) 2 tan θ
(b) 2 sec θ
(c) 2 cosec θ
(d) 2 tan θ sec θ

Solution:

The given expression is $\frac{\tan \theta}{\sec \theta-1}+\frac{\tan \theta}{\sec \theta+1}$.

Simplifying the given expression, we have

$\frac{\tan \theta}{\sec \theta-1}+\frac{\tan \theta}{\sec \theta+1}$

$=\frac{\tan \theta(\sec \theta+1)+\tan \theta(\sec \theta-1)}{(\sec \theta-1)(\sec \theta+1)}$

$=\frac{\tan \theta \sec \theta+\tan \theta+\tan \theta \sec \theta-\tan \theta}{\sec ^{2} \theta-1}$

$=\frac{2 \tan \theta \sec \theta}{\tan ^{2} \theta}$

$=\frac{2 \sec \theta}{\tan \theta}$

$=\frac{2 \frac{1}{\cos \theta}}{\frac{\sin \theta}{\cos \theta}}$

$=2 \frac{1}{\sin \theta}$

$=2 \operatorname{cosec} \theta$

Therefore, the correct option is (c).

 

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