AVERAGE * DAILY TOTAL AMOUNT OF SALES AND NUMBER OF SALES FOR STORE X During the first week of a certain month, how many more sales were made in Store X on Saturday than on Monday?
A.
15
B.
25
C.
30
D.
35
E.
It cannot be determined from the information given.
【简答题】验证下列P(x, y)dx+Q(x, y)dy在整个xOy面内是某一函数u(x, y)的全微分,并求这样的一个函数u(x, y)高等数学复旦大学出版第三版下册课后习题答案习题十一 验证下列P(x, y)dx+Q(x, y)dy在整个xOy面内是某一函数u(x, y)的全微分,并求这样的一个函数u(x, y): (1)( x +2 y )d x +(2 x + y )d y ; (2)2 xy d ...