1.Define [ n ] to be the greatest integer less than or equal to n.Compute the area of the

题目

1.Define [ n ] to be the greatest integer less than or equal to n.Compute the area of the
solution set of [ x ]・[ y ] = 2000.
2.If a and b are the roots of 11x2 – 4x – 2 = 0,then compute the product:
(1 + a + a2 + a3 + ...) (1 + b + b2 + b3 + ...)
3.Compute x/y in simplest terms if x + 1/y= 4 and y + 1/x = 1/4.

答案

1 定义符号[n] 为不大于n的最大整数,计算满足 [ x ]・[ y ] = 2000条件的的点所作成图形的面积.2000=2*2*2*2*5*5*5很明显,x与y是可以互相调换的.x可以有2的因素的情况是5种,可以有5的情况则是4种,一起是5*4=20...