Question

4cosx^2-1=0решить уравнение

Answer 1

4 * (cosx)^2 - 1 = 0
4 * (cosx)^2 = 1
(cosx)^2 = 1/4
cosx = 1/2
cosx = -1/2
x = +-pi/3 + 2*pi*k
x = +-2pi/3 + 2*pi*n