Question

преобразуйте произведение в сумму: cos(pi/4 + y) sin(pi/4 - y)

Answer 1

Ответ:

cos(π/4+y)sin(π/4-y)= 1/2(sin (π/4+у+π/4-у)+sin(π/4+у-π74+у)) =  

= 1/2(sin π/2+sin 2у)= 1/2(1+sin 2у) = 1/2 + 1/2sin2y

Пошаговое объяснение: