Calculate the first-order partial derivative fyf_yfy of the function f(x,y)=ex/yf(x,y) = e^{x/y}f(x,y)=ex/y for y≠0y \neq 0y=0.
−xy2ex/y-\frac{x}{y^2} e^{x/y}−y2xex/y
1yex/y\frac{1}{y} e^{x/y}y1ex/y
−1y2ex/y-\frac{1}{y^2} e^{x/y}−y21ex/y
xy2ex/y\frac{x}{y^2} e^{x/y}y2xex/y