Once you have grasped the quadrant rule it is time to move on and solve more involved equations.

You should have a strategy for solving trig. equations.

Does it factorise when equal to 0?

If it does then quite often each factor can be solved as an equation in its own right. I have three examples here that I would encourage you to look at.

Example (1)

Trig. Equations : Factorising Types f(x)=0 : (Example 1) : ExamSolutions - youtube Video

Example (2)

Trig. Equations : Factorising Types f(x)=0 : (Example 2) : ExamSolutions - youtube Video

Example (3)

Trig. Equations : Factorising Types f(x)=0 : (Example 3) : ExamSolutions - youtube Video