⑩天掌 Teaching Plan on Advanced Mathematics (2)L:x=p(y)c≤y≤d ∫(x,y)s=∫p(y,y}1+p2(y)1 C< 推广:r:x=g(t),y=v(t),z=0().(a≤t≤B) f(x,y, z)ds rnaO,(0.0(0(0)+v2()+o(t (a<B) tianjin Polytechnic univerityTianjin Polytechnic University Teaching Plan on Advanced Mathematics 推广:  : x = (t), y =(t), z =(t). (  t   ) ( ) [ ( ), ( ), ( )] ( ) ( ) ( ) ( , , ) 2 2 2            =  +  +    f t t t t t t dt f x y z ds (2) L : x = ( y) c  y  d. ( , ) [ ( ), ] 1 ( ) . 2 f x y ds f y y y dy d L c =  +  (c  d )