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