Question

Решите
cos2a/cos a - sin a​ + sin(3п/2 +а)

Answer 1

Вроде так

$\frac{cos(2a)}{cos(a)}-sin(a)+sin(3*\frac{\pi }{2}+a)\\\frac{cos(2a)}{cos(a)}-sin(a)+sin(\frac{3\pi }{2}+a)\\\frac{cos(2a)-cos(a)sin(a)-cos(a)^{2} }{cos(a)}\\\frac{cos(a)^{2}-sin(a)^{2}-cos(a)sin(a)-cos(a)^{2}   }{cos(a)}\\\frac{-sin(a)^{2}-cos(a)sin(a) }{cos(a)}\\-\frac{sin(a)^{2}+cos(a)sin(a) }{cos(a)}$