1-sqrt(3)=2cos²x+sqrt(3)sin2x则x等于多少
问题描述:
1-sqrt(3)=2cos²x+sqrt(3)sin2x则x等于多少
答
1-√3=2(1+cos2x)/2+√3sin2x
1-√3=1+cos2x+√3sin2x
2(cos2x*1/2+sin2x*√3/2)=-√3
sin2xcosπ/6+cos2xsinπ/6=√3/2
sin(2x+π/6)=√3/2
2x+π/6=2kπ+π/3,2x+π/6=2kπ+2π/3
x=kπ+π/12,x=kπ+π/4