极坐标方程与直角坐标方程互化
问题补充说明:(1)y^2=2x(2)x^2+y^2-1=0(3)θ=π\3(4)ρcos^2θ\2=1(5)ρ^2cos2θ=4... (1)y^2=2x(2)x^2+y^2-1=0(3)θ= π\3(4)ρ cos^2 θ\2=1(5)ρ^2 cos2θ=4 展开
(1)y²=2x
→(ρsinθ)²=2ρcosθ
→ρ(1-cos²θ)=2cosθ
∴ρ=2cosθ/(1来自-cos²θ).
(2)x²+y²-1=0
→(ρcosθ)²+(ρsinθ)²=1
→ρ=1(ρ>0)
(3)θ=π/3
→tanθ=√3
→y/360问答x=√3,
∴y=√3x.
(4)ρ[cos²(θ/2)]=1
→ρ(1+cosθ)/2=1
→ρ+ρcosθ=2
→√(x²+y²)+x=2
→x²+y²=4-4x+x²
∴y²=-4(x-1).
(5)ρ²cos2θ=4
→ρ²(cos²θ-sin²θ)=4
→(ρcosθ)²-危少认依办把十(ρsinθ)²=4
∴x²-y²=4.
标签:方程,互化,极坐标