Question

спростити tg (a-2п) +ctg ( 3п/2 -a) - sin (п-a)- cos (a+п/2)

Answer 1

$\displaystyle tg(a-2\pi )+ctg(\frac{3\pi }{2} -a)-sin(\pi -a)-cos(a+\frac{\pi }{2}) = -tg(2\pi -a)+tg(a)-sin(a)+sin(a)=tg(a)+tg(a) = 2tg(a)$