√3cos/√(3+sin^2)怎样化简成-√3/√(4tan^2θ+3)
问题描述:
√3cos/√(3+sin^2)怎样化简成-√3/√(4tan^2θ+3)
答
若cosθ≥0,则有
√3cosθ/√(3+sin²θ)
=√3*√[cos²θ/(3+sin²θ)]
=√3*√[cos²θ/(3cos²θ+4sin²θ)]
=√3*√[1/(3+4tan²θ)]
=√3/√(4tan²θ+3)
若cosθ