极坐标ρ^2=12/(4-cos^2θ)转化成普通方程
\u5c06\u6781\u5750\u6807\u65b9\u7a0b\u8f6c\u5316\u4e3a\u666e\u901a\u65b9\u7a0b\u7528x\u548c\u03c1\u8868\u793acos\u03b8\uff0csin\u03b8 x=cos\u03b8*\u03c1 y=\u03c1*sin\u03b8
\u628a2\u221a2 *cos\uff08\u03b1-\u03c0/4(\u5c55\u5f00
\u5f97\u5230p=2 (cosa+sina)
\u7531\u4e8ex=pcosa y=psina p^2=x^2+y^2
\u4ee3\u5165\u90a3\u5f0f\u5f97
p=2x/p+2y/p
\u5373p^2=2x+2y=x^2+y^2
\u6574\u7406\u5f97y^2-2y+1+x^2-2x+1=2
\u5373(y-1)^2 +(x-1)^2=2
\u662f\u4e2a\u5706\u6765\u7684
ρ^2=12/(4-cos^2θ)
解： ρ^2*(4-cos^2θ)=12
4ρ^2-(ρcosθ)^2=12
4(x^2+y^2)-x^2=12
4x^2+4y^2-x^2=12
3x²+4y²=12
公式： x=ρcosθ y=sinθ x²+y²=ρ²
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