⑩天掌 Teaching Plan on Advanced Mathematics 如果积分区域为:c≤y≤d,q1(y)≤x≤q2(y) LY一型] q1(p) x=1(y) D x=p2(y) D Q2(y) ∫∫(x,y)do=∫" q2(y) ∫(x,y)dbx q1(y) tianjin Polytechnic univerityTianjin Polytechnic University Teaching Plan on Advanced Mathematics 如果积分区域为： c  y  d, ( ) ( ). 1 2  y  x   y ［Y－型］ ( ) 2 x =  y ( ) 1 x =  y D c d c d ( ) 2 x =  y ( ) 1 x =  y D ( , ) ( , ) . ( ) ( ) 2 1    = D d c y y f x y d dy f x y dx   