⑩天掌 Teaching Plan on Advanced Mathematics o 3xy+xy dx+(x'+x)dy=0, 3x ydx+xdy+ xy(ydx+xdy) 可积组合法 d(yx+(xy)) 2 原方程的通解为 yx+(xy)2=C.(公式法) tianjin polytechnic dmivendityTianjin Polytechnic University Teaching Plan on Advanced Mathematics (3 ) ( ) 0, 2 2 3 2 x y + xy dx + x + x y dy = 3 ( ) 2 3 x ydx + x dy + xy ydx + xdy ( ) ) 2 1 ( 3 2 = d yx + xy = 0, 原方程的通解为 ( ) . 2 3 1 2 yx + xy = C (公式法) 可积组合法