Question

решите плиз
sin2x sin5x=sin3x sin4x

Answer 1

1)sinx+sin2x+sin3x+sin4x = (sinx+sin3x)+(sin2x+sin4x) =2sin2x× cosx+2sin3x× cosx =2cosx(sin2x+sin3x) =4sin(5x/2)× cos(x/2)× cosx

Answer 2

sinx+sin2x+sin3x+sin4x откуда ты взял это?