+130516 -2sin2x+cosx=0
-2(2sin xcosx) + cosx = 0 factor out cosx
cosx(-4sinx + 1) = 0 set each factor to 0
cosx = 0 and this happens at 90° + n180° where n is an integer
-4sin x + 1 = 0 subtract 1 from each side
-4sinx = -1 divide both sides by -4
sin x = 1/4 and using the sin inverse, we have sin-1(1/4) = x = about 14.48° + n360° and x = about 165.52° + n360° where, again, n is an integer
Here's a graph.........https://www.desmos.com/calculator/77jadcnenw
