#ll e¯ƒƒ(x+y)d(x+3) M (x, y)dx + e f(x+y)d(x+y). 'N(x, y)dy = 0 LA,. 必滿足『交換微分會相等』的口訣. −ƒƒ(x+y)d(x+y).
確定！ 回上一頁
