[题目]-|||-((x)^2+(y)^2)dx-xydy=0;

1.求下列齐次方程的通解：(1)xy-y-sqrt(y^2)-x^(2)=0;(3)（x^2+y^2)dx-xydy=0;(5)(2xsin(y)/(x)+3y

dfrac (dy)(dx)=(x)^2+(y)^2 B . dfrac (dy)(dx)=(x)^2+(y)^2 C .dfrac (dy)(dx)=(x)^

[题目]函数 y=y(x) 由方程 sin ((x)^2+(y)^2)+(e)^x-x(y)^2=0 所-|||-确定,则 dfrac (dy)(dx)= __

[题目]设区域 = (x,y)|{x)^2+(y)^2leqslant 1,xgeqslant 0} , 计算二重-|||-积分 int Ddfrac (1+x

[题目]已知 (x)=(x)^2+(int )_(0)^2f(x)dx, 则∫f-|||-(x) = __ .

证明:函数-|||-f(x,y)= ((x)^2+(y)^2)sin dfrac (1)(sqrt {{x)^2+(y)^2}}, ^2+(y)^2neq 0,

( A ) = (x,y,z)|{x)^2+(y)^2+(z)^2=(a)^2,zgeqslant 0} ( B ) = (x,y,z)|{x)^2+(y)^

[题目]-|||-求函数 (x,y)=(x)^2(2+(y)^2)+yln y 的极值.

[例5] 积分 (int )_(0)^2dx(int )_(0)^sqrt (2x-{x^2)}sqrt ({x)^2+(y)^2}dy= __

[题目]设L为球面 ^2+(y)^2+(z)^2=(a)^22 被平面 x+y+z=0 所-|||-截的圆周,则 (int )_(1)((x)^2+(y)^2)