How do you differentiate -3=xye^(x-y)3=xyexy?

1 Answer
Dec 2, 2015

dy/dx=-(y(x+1))/(x(1-y))dydx=y(x+1)x(1y)

Explanation:

To find the implicit derivative, we'll use the chain rule and product rule. It's important to remember that when differentiating a yy term, a dy/dxdydx term will be spit out thanks to the chain rule.

d/dx[-3=xye^(x-y)]ddx[3=xyexy]

0=ye^(x-y)d/dx[x]+xe^(x-y)d/dx[y]+xyd/dx[e^(x-y)]0=yexyddx[x]+xexyddx[y]+xyddx[exy]

Find each derivative.

d/dx[x]=1ddx[x]=1

d/dx[y]=dy/dxddx[y]=dydx

d/dx[e^(x-y)]=e^(x-y)d/dx[x-y]=e^(x-y)(1-dy/dx)=e^(x-y)-e^(x-y)dy/dxddx[exy]=exyddx[xy]=exy(1dydx)=exyexydydx

Plug them back in and solve for dy/dxdydx.

0=ye^(x-y)+xe^(x-y)dy/dx+xye^(x-y)-xye^(x-y)dy/dx0=yexy+xexydydx+xyexyxyexydydx

-xye^(x-y)-ye^(x-y)=dy/dx(xe^(x-y)-xye^(x-y))xyexyyexy=dydx(xexyxyexy)

(-xye^(x-y)-ye^(x-y))/(xe^(x-y)-xye^(x-y))=dy/dxxyexyyexyxexyxyexy=dydx

dy/dx=(e^(x-y)(-xy-y))/(e^(x-y)(x-xy))dydx=exy(xyy)exy(xxy)

dy/dx=-(y(x+1))/(x(1-y))dydx=y(x+1)x(1y)