高数：用参数方程实现直角坐标系与极坐标系的互换 极坐标系参数方程与直角坐标系下的参数方程如何互相转化？
\u9ad8\u6570\u76f4\u89d2\u5750\u6807\u65b9\u7a0b\u548c\u53c2\u6570\u65b9\u7a0b\u4ee5\u53ca\u6781\u5750\u6807\u65b9\u7a0b\u7684\u8f6c\u6362\u3002\u5706\u5fc3\u4e3a(1/2,5/2)\uff0c\u534a\u5f84\u4e3a\u221a2/2
\u53c2\u6570\u65b9\u7a0b\u4e3a\uff1ax=(\u221a2/2)*cos\u03b8+1/2\uff0cy=(\u221a2/2)*sin\u03b8+5/2\uff0c\uff080<=\u03b8<2\u03c0\uff09
\u4ee4x=\u03c1cos\u03b8\uff0cy=\u03c1sin\u03b8\uff0c\u4ee3\u5165\u539f\u65b9\u7a0b
\u03c1^2-\u03c1cos\u03b8-5\u03c1sin\u03b8+6=0
\u03c1(5sin\u03b8+cos\u03b8)=\u03c1^2+6
\u221a26*sin[\u03b8+arcsin(1/\u221a26)]=(\u03c1^2+6)/\u03c1
sin[\u03b8+arcsin(1/\u221a26)]=(\u03c1^2+6)/(\u221a26\u03c1)
\u03b8+arcsin(1/\u221a26)=arcsin[(\u03c1^2+6)/(\u221a26\u03c1)]\u6216\u03c0-arcsin[(\u03c1^2+6)/(\u221a26\u03c1)]
\u03b8=arcsin[(\u03c1^2+6)/(\u221a26\u03c1)]-arcsin(1/\u221a26)
\u6216\u03c0-arcsin[(\u03c1^2+6)/(\u221a26\u03c1)]-arcsin(1/\u221a26)
\u6269\u5c55\u8d44\u6599
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\u6211\u8bf4\u7684\u53e3\u8bed\u5316\u4e00\u70b9\uff0c\u6781\u5750\u6807\u65b9\u7a0b\u8f6c\u5316\u4e3a\u76f4\u89d2\u5750\u6807\u65b9\u7a0b\u5c31\u662f\u901a\u8fc7\u7ed9\u4f60\u7684\u4e24\u4e2a\u7b49\u5f0f\uff0c\u60f3\u529e\u6cd5\u628a\u4e24\u4e2a\u7b49\u5f0f\u7ed3\u5408\uff0c
\u5e76\u628a\u53c2\u6570\u6d88\u9664\uff0c\u5c31\u53ef\u4ee5\u4e86\uff1b\u76f4\u89d2\u5750\u6807\u7cfb\u8f6c\u5316\u4e3a\u6781\u5750\u6807\u65b9\u7a0b\u5c31\u770b\u662f\u4ec0\u4e48\u56fe\u5f62\u4e86\uff0c\u6bcf\u79cd\u56fe\u5f62\u90fd\u6709\u81ea\u5df1\u7684\u516c\u5f0f\u7684\u3002\u3002\u3002\u4e0d\u60f3\u6253\uff0c\u4f60\u5982\u679c\u8981\u770b\u518d\u8ffd\u95ee
x=ρcos φ，y=ρsin φ
直角坐标与极坐标的关系：
ρ²=x²+y²
tan φ=y/x
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