Question

dosto please yaar isko solve kro acche se ajeeb bat hai koi lga nhi pa rha h isko ​

Answer 1

Step-by-step explanation:

$\frac{\cos(\pi \: + x) \cos( - x) }{ \sin(\pi - x) \cos( \frac{\pi}{2} + x ) } \\ \\ = \frac{( - \cos(x)) \cos(x) }{ \sin(x) ( - \sin(x) ) } \\ \\ = \frac{ \cos^2(x) }{ \sin^2(x) } \\ \\ = \cot^2(x)$

We know that....

$\cos(\pi + x) = - cos(x) \\ \cos( - x) = \cos(x) \\ \cos( \frac{\pi}{2} + x ) = - \</strong><strong>sin</strong><strong>(x) \\ \\ \sin(\pi \: - x) = \sin(x)$