求法线方程和切线方程 怎么求函数的切线方程和法线方程？
\u5207\u7ebf\u65b9\u7a0b\u548c\u6cd5\u7ebf\u65b9\u7a0b\u7684\u6c42\u6cd5\u51fd\u6570\u56fe\u5f62\u5728\u67d0\u70b9(a,b)\u7684\u5207\u7ebf\u65b9\u7a0by=kx+b:
\u5148\u6c42\u659c\u7387k,\u7b49\u4e8e\u8be5\u70b9\u51fd\u6570\u7684\u5bfc\u6570\u503c\uff1b
\u518d\u7528\u8be5\u70b9\u7684\u5750\u6807\u503c\u4ee3\u5165\u6c42b\uff1b
\u5207\u7ebf\u65b9\u7a0b\u6c42\u6bd5\uff1b
\u6cd5\u7ebf\u65b9\u7a0b\uff1a
y=mx+c
m=\u4e001/k\uff1b k\u4e3a\u5207\u7ebf\u659c\u7387
\u518d\u628a\u5207\u70b9\u5750\u6807\u4ee3\u5165\u6c42\u5f97c\uff1b
\u6cd5\u7ebf\u65b9\u7a0b\u6c42\u6bd5
\u6c42\u5bfc
y'=2x-3
y'(1)=2-3=-1
\u8be5\u66f2\u7ebf\u5728\u70b9\uff081,-1\uff09\u5904\u7684\u5207\u7ebf\u65b9\u7a0b\uff1a
y+1=-1(x-1)=-x+1
\u5373,y=-x
\u6cd5\u7ebf\u65b9\u7a0b:y+1=(x-1)
\u5373 y=x-2
\u5207\u7ebf\u65b9\u7a0b\u662f\u7814\u7a76\u5207\u7ebf\u4ee5\u53ca\u5207\u7ebf\u7684\u659c\u7387\u65b9\u7a0b\uff0c\u6d89\u53ca\u51e0\u4f55\u3001\u4ee3\u6570\u3001\u7269\u7406\u5411\u91cf\u3001\u91cf\u5b50\u529b\u5b66\u7b49\u5185\u5bb9\u3002
\u65b9\u7a0b\u7684\u8bc1\u660e
\u5411\u91cf\u6cd5
\u8bbe\u5706\u4e0a\u4e00\u70b9A\u4e3a,\u5219\u8be5\u70b9\u4e0e\u5706\u5fc3O\u7684\u5411\u91cf\u3002
\u56e0\u4e3a\u8fc7\u8be5\u70b9\u7684\u5207\u7ebf\u4e0e\u8be5\u65b9\u5411\u534a\u5f84\u5782\u76f4\uff0c\u5219\u6709\u5207\u7ebf\u65b9\u5411\u4e0a\u7684\u5355\u4f4d\u5411\u91cf\u4e0e\u5411\u91cfOA\u7684\u70b9\u79ef\u4e3a0\u3002
\u8bbe\u76f4\u7ebf\u4e0a\u4efb\u610f\u70b9B\u4e3a(x,y)\u3002
\u5219\u5bf9\u4e8e\u76f4\u7ebf\u65b9\u5411\u4e0a\u7684\u5411\u91cf\u3002
\u6709\u5411\u91cfAB\u4e0eOA\u7684\u70b9\u79ef\u3002
法线斜率2；法线方程：y-1=2(x-2)
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