What is the implicit derivative of 1=x/y-xtany1=xyxtany?

1 Answer
Dec 13, 2015

dy/dx=-(y(ytany-1))/(x(1+y^2sec^2y))dydx=y(ytany1)x(1+y2sec2y)

Explanation:

d/dx[1=x/y-xtany]ddx[1=xyxtany]

Find each derivative.

d/dx[1]=0ddx[1]=0

d/dx[x/y]=(yd/dx[x]-xd/dx[y])/y^2=(y-xdy/dx)/y^2ddx[xy]=yddx[x]xddx[y]y2=yxdydxy2

d/dx[xtany]=tanyd/dx[x]+xd/dx[tany]=tany+xsec^2ydy/dxddx[xtany]=tanyddx[x]+xddx[tany]=tany+xsec2ydydx

Plug the derivatives back in.

0=(y-xdy/dx)/y^2-tany-xsec^2ydy/dx0=yxdydxy2tanyxsec2ydydx

tany=(y-xdy/dx)/y^2-xsec^2ydy/dxtany=yxdydxy2xsec2ydydx

y^2tany=y-xdy/dx-xy^2sec^2ydy/dxy2tany=yxdydxxy2sec2ydydx

y^2tany-y=dy/dx(-x-xy^2sec^2y)y2tanyy=dydx(xxy2sec2y)

dy/dx=-(y(ytany-1))/(x(1+y^2sec^2y))dydx=y(ytany1)x(1+y2sec2y)