Here's an example of solving equations using trig functions.


2sin*sin2x - cosx =0

(know that sin2x = 2sinxcosx, therefore we have

4sin^xcosx - cosx =0

cosx(4sin^2(x) - 1) = 0

cosx = 1,  4sin^2(x) = 1

x = 0,       sin^2(x) = 1/4, sinx = +/- sqrt(2)/2

x= pi/4, 3pi/4, 5pi/4 and 7pi/4