давайте разберем это по частям:
sin(90°+a) = sin(90°)cos(a) + cos(90°)sin(a) = 1cos(a) + 0sin(a) = cos(a)cos(180°-a) = cos(180°)cos(a) + sin(180°)sin(a) = -1cos(a) + 0sin(a) = -cos(a)sin(a)cos(a)tg(a) = sin(a)cos(a)sin(a)/cos(a) = sin(a)sin(a) = sin^2(a)
Итак, упрощенное выражение будет: cos(a) (-cos(a)) - sin(a) sin(a) = -cos(a)^2 - sin(a)^2 = -1.
давайте разберем это по частям:
sin(90°+a) = sin(90°)cos(a) + cos(90°)sin(a) = 1cos(a) + 0sin(a) = cos(a)
cos(180°-a) = cos(180°)cos(a) + sin(180°)sin(a) = -1cos(a) + 0sin(a) = -cos(a)
sin(a)cos(a)tg(a) = sin(a)cos(a)sin(a)/cos(a) = sin(a)sin(a) = sin^2(a)
Итак, упрощенное выражение будет: cos(a) (-cos(a)) - sin(a) sin(a) = -cos(a)^2 - sin(a)^2 = -1.