切线斜率怎么求 切线的斜率怎么求
\u51fd\u6570\u70b9\u7684\u5207\u7ebf\u65b9\u7a0b\u600e\u4e48\u6c42k=(y1-y2)/(x1-x2)\u3002
\u659c\u7387\u8868\u793a\u4e00\u6761\u76f4\u7ebf(\u6216\u66f2\u7ebf\u7684\u5207\u7ebf)\u5173\u4e8e(\u6a2a)\u5750\u6807\u8f74\u503e\u659c\u7a0b\u5ea6\u7684\u91cf\u3002\u5b83\u901a\u5e38\u7528\u76f4\u7ebf(\u6216\u66f2\u7ebf\u7684\u5207\u7ebf)\u4e0e(\u6a2a)\u5750\u6807\u8f74\u5939\u89d2\u7684\u6b63\u5207\uff0c\u6216\u4e24\u70b9\u7684\u7eb5\u5750\u6807\u4e4b\u5dee\u4e0e\u6a2a\u5750\u6807\u4e4b\u5dee\u7684\u6bd4\u6765\u8868\u793a\u3002
\u76f4\u7ebf\u5bf9X \u8f74\u7684\u503e\u659c\u89d2\u03b1\u7684\u6b63\u5207\u503ctg\u03b1\u79f0\u4e3a\u8be5\u76f4\u7ebf\u7684\u201c\u659c\u7387\u201d\uff0c\u5e76\u8bb0\u4f5ck\uff0ck=tg\u03b1\u3002\u89c4\u5b9a\u5e73\u884c\u4e8eX\u8f74\u7684\u76f4\u7ebf\u7684\u659c\u7387\u4e3a\u96f6\uff0c\u5e73\u884c\u4e8eY\u8f74\u7684\u76f4\u7ebf\u7684\u659c\u7387\u4e0d\u5b58\u5728\u3002\u5bf9\u4e8e\u8fc7\u4e24\u4e2a\u5df2\u77e5\u70b9(x1\uff0cy1) \u548c (x2\uff0cy2)\u7684\u76f4\u7ebf\uff0c\u82e5x1\u2260x2\uff0c\u5219\u8be5\u76f4\u7ebf\u7684\u659c\u7387\u4e3ak=(y1-y2)/(x1-x2)\u3002
\u6269\u5c55\u8d44\u6599\uff1a
\u66f2\u7ebf\u659c\u7387\uff1a
\u66f2\u7ebf\u7684\u4e0a\u67d0\u70b9\u7684\u659c\u7387\u5219\u53cd\u6620\u4e86\u6b64\u66f2\u7ebf\u7684\u53d8\u91cf\u5728\u6b64\u70b9\u5904\u7684\u53d8\u5316\u7684\u5feb\u6162\u7a0b\u5ea6\u3002\u66f2\u7ebf\u7684\u53d8\u5316\u8d8b\u52bf\u4ecd\u53ef\u4ee5\u7528\u8fc7\u66f2\u7ebf\u4e0a\u4e00\u70b9\u7684\u5207\u7ebf\u7684\u659c\u7387\u5373\u5bfc\u6570\u6765\u63cf\u8ff0\u3002\u5bfc\u6570\u7684\u51e0\u4f55\u610f\u4e49\u662f\u8be5\u51fd\u6570\u66f2\u7ebf\u5728\u8fd9\u4e00\u70b9\u4e0a\u7684\u5207\u7ebf\u659c\u7387\u3002
f'(x)>0\u65f6\uff0c\u51fd\u6570\u5728\u8be5\u533a\u95f4\u5185\u5355\u8c03\u9012\u589e\uff0c\u66f2\u7ebf\u5448\u5411\u4e0a\u7684\u8d8b\u52bf\uff1bf'(x)<0\u65f6\uff0c\u51fd\u6570\u5728\u8be5\u533a\u95f4\u5185\u5355\u8c03\u51cf\uff0c\u66f2\u7ebf\u5448\u5411\u4e0b\u7684\u8d8b\u52bf\u3002
\u5728\uff08a,b\uff09f''(x)0\u65f6\uff0c\u51fd\u6570\u5728\u8be5\u533a\u95f4\u5185\u7684\u56fe\u5f62\u662f\u51f9\u7684\u3002
\u53c2\u8003\u8d44\u6599\u6765\u6e90\uff1a\u767e\u5ea6\u767e\u79d1-\u659c\u7387
比如：点P(Xo,yo)在曲线y=f(x)上,f`(x)为函数y=f(x)导函数,k为过点P的切线的斜率,
则k=f`(Xo)
答：切线斜率等于切点所在的函数在切点处的导数（切线斜率必须存在）
比如：点P(Xo,yo)在曲线y=f(x)上，f`(x)为函数y=f(x)导函数,k为过点P的切线的斜率，
则k=f`(Xo)
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