there are 2 questions Find all solutions to the equation 2 c

there are 2 questions

Find all solutions to the equation 2 cos theta + Squareroot 3 = 0. Find all solutions to the equation 2 cos^2 theta + sin theta = 1.

1) 2*cos + 3 = 0

2*cos = -3

cos = -3/2

= arccos(-3/2) = 150, 210 degree

2) 2*cos^2 + sin = 1

2*(1 - sin^2 ) = 1 - sin

2*(1 - sin)(1 + sin) = 1 - sin

2*(1 + sin) = 1

sin = -1/2 =======> = 210, 330 degree