C1. соs(3П/2 +2х)= сosx

Question

C1. соs(3П/2 +2х)= сosx

Answer 1

соs(3П/2 +2х)= сosx

sin2x = cosx

sin2x - cosx = 0

2sinx*cosx - cosx = 0

cosx(2sinx -1) = 0

 

1) cosx = 0

x = π/2 +2πn, n∈Z

 

2) 2sinx -1 = 0

sinx = 1/2

x =  arcsin 1/2 + πk

x =  π/6 + πk, k∈Z

Answer 2

cos(3π/2+2x)=cosx;

3π/2+2x=x;

x=-3π/2. - вы гоните что-ли?))