Question

БИСТРО ПЖжжжжжжжжжжжжжжжжжжж

Answer 1

$\displaystyle ctg\frac{5\pi }{4}*tg\frac{5\pi }{4}+sin\frac{5\pi }{4}=1+sin(\pi +\frac{\pi }{4})=1-sin\frac{\pi }{4}=1-\frac{\sqrt{2}}{2}=\frac{2-\sqrt{2}}{2}$