Question

4sin(a-3pi)-cos(3pi2+a))(5sin(a-pi)) помогите найти значение выражения

Answer 1

$4sin(a-3pi)-frac{cos(3pi/2+a)}{5sin(a-pi)}=-4sin(a)-frac{cos(pi/2+a)}{-5sin(a)}=\=-4sin(a)+frac{-sin(a)}{5sin(a)}=frac{1}{5}-4sin(a)$