√3X+√(1-X²)=√3sinθ+cosθ √ 为根号
2个回答

√3X+√(1-X²)=√3sinθ+cosθ =2sin(θ+π/6)

移项,得 √(1-X²)=2sin(θ+π/6) -√3X

平方,得 1-X²=[2sin(θ+π/6) -√3X]^2

展开,得 4X²- 4√3sin(θ+π/6)x +(√3sinθ+cosθ )^2-1=0

化简,得 X²- √3sin(θ+π/6)x +sinθsin(θ+π/3)=0

分解,得 (x-sinθ)(x-(θ+π/3))=0

从而,得 x=sinθ或x=(θ+π/3)

带入检验即可