sin 2 x + 4 3 sin x cos x + cos 2 x + 2 = 0 sin 2 x + 4 3 sin x cos x + cos 2 x + 2 cos 2 x + 2 sin 2 x = 0 3 sin 2 x + 4 3 sin x cos x + 3 cos 2 x = 0 3 tan 2 x + 4 3 tan x + 3 = 0 tan x 12 = 4 3 ± ( 4 3 ) 2 36 6 = 4 3 ± 48 36 6 = 4 3 ± 12 6 = 4 3 ± 2 3 6 { tan x 1 = 4 3 + 2 3 6 = 3 3 x 1 = π 6 + k π tan x 2 = 4 3 2 3 6 = 3 x 2 = 2 π 3 + k π sin^2 x + 4 sqrt 3 sin x cos x +cos^2 x + 2 = 0 newline newline sin^2 x + 4 sqrt 3 sin x cos x +cos^2 x + 2 cos^2 x + 2 sin^2 x = 0 newline newline 3 sin^2 x + 4 sqrt 3 sin x cos x +3 cos^2 x = 0 newline newline 3 tan^2 x + 4 sqrt 3 tan x +3 = 0 newline newline tan x_12= { -4 sqrt 3 +- sqrt{(4 sqrt 3 )^2-36} } over { 6 } ={ -4 sqrt 3 +- sqrt{48-36} } over { 6} = { -4 sqrt 3 +- sqrt{12} } over { 6 }= { - 4 sqrt 3 +- 2 sqrt{3} } over { 6 } toward "" newline newline toward left lbrace stack{tan x_1 = { - 4 sqrt 3 + 2 sqrt{3} } over { 6 } = - {sqrt 3 over 3} toward x_1 =-{ %pi over 6} + k %pi # tan x_2 = { - 4 sqrt 3 - 2 sqrt{3} } over { 6 }=- sqrt 3 toward x_2= {2 %pi} over 3 + k %pi} right none