题目
设z=arctan(x)/(y),则z_(x)+z_(y)=()A. (y-x)/(x^2)+y^(2)B. (x-y)/(x^2)+y^(2)C. (y-x)/(x^2)-y^(2)D. (x-y)/(x^2)-y^(2)
设$z=\arctan\frac{x}{y}$,则$z_{x}+z_{y}=$()
A. $\frac{y-x}{x^{2}+y^{2}}$
B. $\frac{x-y}{x^{2}+y^{2}}$
C. $\frac{y-x}{x^{2}-y^{2}}$
D. $\frac{x-y}{x^{2}-y^{2}}$
题目解答
答案
A. $\frac{y-x}{x^{2}+y^{2}}$