Using the Step by Step Equation Solver APP from www.TiNspireApps.com for the TiNspire CX CAS you select

the first option: 1: Step by Step Equation Solver

Enter any equation and view the steps until final answer is derived.

Since we are solving a trigonometric (thus periodic) equation in above example

we obtain infinity many solutions whose setup is displayed in the

last line. n11 represents a constant, think of it as constant K as typically used in text books.

If you set n11 equal to 0 for the first expression for the solution x you recognize the solution

derived step by step.