3
sin
2
x
+
2
3
sin
x
cos
x
+
5
cos
2
x
=
3
3
sin
2
x
+
2
3
sin
x
cos
x
+
5
cos
2
x
−
3
cos
2
x
−
3
sin
2
x
=
0
2
cos
2
x
+
2
3
sin
x
cos
x
=
0
cos
x
(
cos
x
+
3
sin
x
)
=
0
→
{
cos
x
1
=
0
→
x
1
=
π
2
+
k
π
cos
x
+
3
sin
x
=
0
→
3
tan
x
=
−
1
→
tan
x
=
−
3
3
→
x
2
=
−
π
6
+
k
π
3 sin^2 x + 2 sqrt 3 sin x cos x + 5 cos^2 x = 3 newline newline
3 sin^2 x + 2 sqrt 3 sin x cos x + 5 cos^2 x - 3 cos^2 x - 3 sin^2 x = 0 newline newline
2 cos^2 x + 2 sqrt 3 sin x cos x = 0 newline newline
cos x ( cos x + sqrt 3 sin x ) = 0 toward left lbrace stack{ alignl cos x_1 =0 toward x_1 = {%pi over 2}+ k %pi # cos x + sqrt 3 sin x =0 toward sqrt 3 tan x = -1 toward tan x = - {sqrt 3 over 3} toward x_2 = -{%pi over 6} + k %pi } right none