求由方程y x3=1 xe y所确定的隐函数y=f(x)的导数
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方程两边同时求x对y的导:y+xdy/dx+1/x+2ydy/dx=0,dy/dx=-(y+1/x)/(x+2y),dy=-(y+1/x)dx/(x+2y)
xy+lnx+lny=1对x求导y+xy'+1/x+y'/y=0(其中y'表示dy/dx)所以y'=(-1/x-y)/(x+1/y)=-(y+xy^2)/(x^2y+x)
y=x+lny两边同时求导得dy/dx=1+1/y*dy/dx(1-1/y)dy/dx=1dy/dx=1/(1-1/y)=y/(y-1)
方程两边求关x的导数ddx(xy)=(y+xdydx); ddxex+y=ex+y(1+dydx);所以有 (y+xdy
左右对x求导有y'/y=sec²(xy)(y+xy')整理有y'=y²/(cos(xy)-xy)所以dy=(y²/(cos(xy)-xy))dx
对x求导数可以得到-sin(x+y)*(1+y')+e^y*y'=0所以y'(e^x-sin(x+y))=sin(x+y)所以y'=sin(x+y)/(e^x-sin(x+y))再问:兄弟有QQ吗再答
z对x的偏导xy+yz+zx=1y+yfx'+z+xfx'=0z对y的偏导x+z+yfy'+xfy'=0z对y的偏导1+fx'+yfxy"+fy'+xfxy"=01+(fx'+fy')+(x+y)fx
此题要考察隐函数导数的求法先求出该曲线与y轴交点y³=1+xe^y令x=0,则y³=1即y=1,交点坐标(0,1)方程两边同时对x求导数:3y²·y′=(x)′·e^y+
这道题考查隐函数求导方法,求出x=0的倒数就是切线的斜率啦,k1=y‘,然后法线的斜率就是-1/y’.x=0代入方程,得sin0+lny=0即lny=-1解得y=1/e也就是说x=0处曲线上的点是(0
y+xy'+y'/y=0//对xy和lny分别求导,注意y是x的函数y'(x+1/y)=-y//移项,合并同类项y'=-y²/(xy+1)
xy+lny=1两边求导y+xy'+y'/y=0y'=-y/(x+1/y)=-y^2/(xy+1)
两边求导:y+xy'+y‘/y=0将x=0带入得到:y'=--y^2
y-1=xe^y两边同时对x求导得y'=e^y+xe^y*y'(1-xe^y)y'=e^yy'=e^y/(1-xe^y)=e^y/(2-y)y''=(e^y*y'+e^y*y')/(2-y)²
xy+e^y=1e^y(0)=1y(0)=0xy'+y+e^yy'=00+y(0)+y'(0)=0y'(0)=0xy''+y'+y'+e^yy''+(y')^2e^y=00+2y'(0)+y''(0)
①x≥0y≥0,有x+y=1,y=-x+1②x≥0y
dy/dx-e^y-x*e^ydy/dx=0dy/dx(1-x*e^y)=e^ydy/dx=e^y/(1-x*e^y)
两边对x求导得:y'=e^y+xy'e^yy'=e^y/(1-xe^y)y''=dy'/dx=[y'e^y(1-xe^y)-(-e^y-xy'e^y)e^y]/(1-xe^y)²=(2-x)
两边对x求导:y'=e^y+xy'e^y得:y'=e^y/(1-xe^y)再问:怎么感觉不对捏再答:是不是指数为y+1,而不是y呀?再问:指数就是y吖我题目没错再答:指数是y的话,我做的就没错。
F(x,y,z)=xy+e^xz-zlny-1.Fx=y+ze^xzFy=x-z/yFz=xe^xz-lnyz对x的偏导:-Fx/Fz=-(y+ze^xz)/(xe^xz-lny)z对y的偏导:-Fy