(2cosx+1) (3tgx+1)= 0
2cosx + 1 = 0 3tgx + 1 = 0 2cosx = -1 3tgx = -1 cosx = -0,5 tgx = -1/3 cosx = -0,5 x=arccos(-0,5) + 2pk x = -arccos(-0,5) + 2pk x1=2p/3 + 2pk x2= -2p/3 + 2pk