Question

(2cosx+1) (3tgx+1)= 0

Answer 1

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