对坐标的曲线积分 1定义:∫P(x,y)d=lm∑P(5,m)Ax -> 0 ∫Q(x,y)=lim∑Q(5,n)4 -) P(x,],a)dx=lim >P(Si, ni, si)Ax; 九- 0 i=1 Q(, y, z)dy=lim ∑Q(,n,)An 入->0 R(x,y,)z=lim∑R(,n,,)△z 入→>0 K心二. 对坐标的曲线积分 1.定义: ( , ) lim ( , ) 1 0   → = =  n i i i i L P x y dx P   x  ( , ) lim ( , ) 1 0   → = =  n i i i i L Q x y dy Q   y  ( , , ) lim ( , , ) . 1 0 i i i n i P x y z dx = P i x  =  →     ( , , ) lim ( , , ) . 1 0 i i i n i i Q x y z dy = Q    y  =  → ( , , ) lim ( , , ) . 1 0 i i i n i i R x y z dz = R    z  =  →