How do you implicitly differentiate csc(x^2/y^2)=e^(xy) csc(x2y2)=exy?

1 Answer
Sep 2, 2017

dy/dx=(2xcsc(x^2/y^2)cot(x^2/y^2)+y^3e^(xy))/(xy(2xcsc(x^2/y^2)cot(x^2/y^2)-ye^(xy))dydx=2xcsc(x2y2)cot(x2y2)+y3exyxy(2xcsc(x2y2)cot(x2y2)yexy)

Explanation:

Implicit differentiation is no different from explicit differentiation. Just remember that differentiating a function of yy causes the chain rule to be in effect. Recall also that d/dxcscx=-cscxcotxddxcscx=cscxcotx and d/dxe^x=e^xddxex=ex.

csc(x^2/y^2)=e^(xy)csc(x2y2)=exy

d/dxcsc(x^2/y^2)=d/dxe^(xy)ddxcsc(x2y2)=ddxexy

-csc(x^2/y^2)cot(x^2/y^2)*d/dx(x^2y^-2)=e^(xy)*d/dx(xy)csc(x2y2)cot(x2y2)ddx(x2y2)=exyddx(xy)

Use the product rule to find these derivatives. Recall that while d/dxx^2=2xddxx2=2x, d/dxy^2=2ydy/dxddxy2=2ydydx.

-csc(x^2/y^2)cot(x^2/y^2)(2xy^-2-2x^2y^-1dy/dx)=e^(xy)(y+xdy/dx)csc(x2y2)cot(x2y2)(2xy22x2y1dydx)=exy(y+xdydx)

Expanding and rearranging to group dy/dxdydx terms:

((2x^2csc(x^2/y^2)cot(x^2/y^2))/y-xe^(xy))dy/dx=(2xcsc(x^2/y^2)cot(x^2/y^2))/y^2+ye^(xy)2x2csc(x2y2)cot(x2y2)yxexydydx=2xcsc(x2y2)cot(x2y2)y2+yexy

Common denominators:

((2x^2csc(x^2/y^2)cot(x^2/y^2)-xye^(xy))/y)dy/dx=(2xcsc(x^2/y^2)cot(x^2/y^2)+y^3e^(xy))/y^22x2csc(x2y2)cot(x2y2)xyexyydydx=2xcsc(x2y2)cot(x2y2)+y3exyy2

Solving for dy/dxdydx:

dy/dx=(2xcsc(x^2/y^2)cot(x^2/y^2)+y^3e^(xy))/y^2*y/(2x^2csc(x^2/y^2)cot(x^2/y^2)-xye^(xy))dydx=2xcsc(x2y2)cot(x2y2)+y3exyy2y2x2csc(x2y2)cot(x2y2)xyexy

dy/dx=(2xcsc(x^2/y^2)cot(x^2/y^2)+y^3e^(xy))/(xy(2xcsc(x^2/y^2)cot(x^2/y^2)-ye^(xy))dydx=2xcsc(x2y2)cot(x2y2)+y3exyxy(2xcsc(x2y2)cot(x2y2)yexy)