题目
3.单选题(1分)设z=arctan(xy),则dz=()A. (1)/(1+x^2)y^(2)(ydx+xdy)B. ydx-xdyC. (1)/(1+x^2)y^(2)(ydx-xdy)D. ydx+xdy
3.单选题(1分)
设z=arctan(xy),则dz=()
A. $\frac{1}{1+x^{2}y^{2}}(ydx+xdy)$
B. ydx-xdy
C. $\frac{1}{1+x^{2}y^{2}}(ydx-xdy)$
D. ydx+xdy
题目解答
答案
A. $\frac{1}{1+x^{2}y^{2}}(ydx+xdy)$