求由方程xy lny=1所确定的函数y=f(x)在点m(1,1)处的切线方程-搜答案-智慧作业帮

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)

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

隐函数求导设z=x²y²-cos(xy)dy/dx=-(δz/δx)/(δz/δy)=-(2xy²+ysin(xy))/(2x²y+xsin(xy))=-y/x

dz=y*x^(y-1)/cosz*dx+x^y*lnx/cosz*dy

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'=cos(x+y)(1+y')y'=cos(x+y)/(1-cos(x+y))

dx=(1+lnt)dtdy=(t+2tlnt)dt∴dy/dx=(t+2tlnt)/(1+lnt)……（1）有原参数方程可以得到t=y/x,lnt=x^2/y代入（1）中即可得到答案.自己代吧我做的

对x求导,e^z*z'(x)=yz+xyz'(x),z'(x)=yz/(e^z-xy)对y求导,e^z*z'(y)=xz+xyz'(y),z'(y)=xz/(e^z-xy)

y'=-2sin2(x+y)-2y'sin2(x+y)(1+2sin2(x+y))y'=-2sin2(x+y)y'=-2sin2(x+y)/(1+2sin2(x+y))

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

-e^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

①x≥0y≥0,有x+y=1,y=-x+1②x≥0y

xe^f(y)=ln2009e^ye^f(y)+xe^f(y)*f'(y)*y'=y'e^f(y)(1+xf'y')=y'e^f*f'*y

y+x*y'=e^(x+y)*(1+y')∴dy/dx=[e^(x+y)-y]/[x-e^(x+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。