Cos (π+a) делить на tg (π/2-a) * ctg (3π/2+a)

Cos (π + a) / (tg (π/2 - a) * ctg (3π/2 + a));

Cos (π + a) / (sin (π/2 - a) / cos (pi/2 - a) * cos (3π/2 + a) / sin (3 * pi/2 + a));

(cos pi * cos a - sin pi * sin a) / ((sin pi/2 * cos a - cos pi/2 * sin a) / (cos pi/2 * cos a + sin pi/2 * sin a) * (cos 3*pi/2 * sin a - sin 3 * pi/2 * sin a) / (sin 3 * pi/2 * cos a + cos 3 * pi/2 * sin a));

(-1 * cos a - 0 * sin a) / ((1 * cos a - 0 * sin a) / (0 * cos a + 1 * sin a) * (0 * sin a - (-1) * sin a) / ((-1) * cos a + 0 * sin a));

cos a / (cos a/sin a * ( - (-1) * sin a) / ((-1) * cos a));

cos a / (cos a/sin a * sin a / ( - cos a));

cos a / (-1);

-cos a.