OKay, so how would this equation be solved,
so I've tried this way...
and after that, i'm stuck.
Well this has multiple answers now doesn't it? You've factored correctly. You know that you're equation will be zero when cos(x)=0 and when 1-2sin(x)=0. So solve for both. I'll start you. The first time cos(x)=0 starting from 0 and moving positively is at and it will do so at every at every after that. So I would write one zero as where k is any integer.