Answer:
x = 2k
is the solution of this equation.
Explanation:
This question is related to trigonometric equations.
The given equation is,

We have to find the solutions of this equation.
Put

+ 3cosx - 1 = 2
= 0
For this equation only cosx = 1 is possible solution.
Cosx = 1 happens when x is a multiple of 2

So x = 2k
is the solution of this equation.