Question

Решите пожалуйста...

Answer 1

$frac{25}{sin(-frac{25pi}{4})cdot cosfrac{25pi}{4}} =frac{25}{-frac{1}{2}sin(2cdot frac{25pi }{4})} =-frac{50}{sinfrac{25pi}{2}}=-frac{50}{sin(12pi +frac{pi}{2})}=\\=-frac{50}{sinfrac{pi}{2}}=-frac{50}{1}=-50$