Question

sin(x+270°)-cos(3x+720°), 40°<x<90°​

Answer 1

Ответ:

Объяснение:

sin(x+270°)-cos(3x+720°)=-cosx+cos3x=cos3x-cosx=-2sin2xsinx

sin(x+270°)=-cosx;

cos(3x+720°)=cos(3x+2*360°)=cos3x;

sin(x+270°)-cos(3x+720°)=-2sin2xsinx