⑩天掌 Teaching Plan on Advanced Mathematics o 1公式法:O(P)=0() O ax aP du 80 au +p 。+ ay ax a Q两边同除山 0nμ_P 求解不容易 ax ayay ax 特殊地: a.当以只与有关时:,=0,0=, tianjin polytechnic dmivendityTianjin Polytechnic University Teaching Plan on Advanced Mathematics 1.公式法: , ( ) ( ) x Q y P   =      x Q x Q y P y P   +   =   +       两边同除， x Q y P y P x Q   −   =   −   ln  ln  求解不容易 特殊地: a.当只与x有关时; = 0,   y  , dx d x   =  