Question

七年级下册数学练习册第四页第五题怎么做？

5.用下面的方法确定√2的前几个小数位上的数字. （1）阅读理解： 我们知道，正方形面积越大，其边长也越大，即如果0＜a＜b，那么0＜√a＜√b. 因为1^2＜2＜2^2，所以1＜√2＜2，可知√2的整数部分是1. （ i ）取（1+2）/2=1.5，由1.5^2=2.25＞2，得1＜√2＜1.5. （ ii ）取（1+1.5）/2=1.25，由1.25^2＜1.6＜2，得1.25＜√2＜1.5. （2）操作实践： 继续像（ i ）、（ ii ）那样取值和比较，确定√2的十分位和百分位上的数字.

Answer 1

(1.25+1.5)=1.375 1.375^2<2<1.5^2 1.375<√2<1.5 (1.375+1.5)/2=1.4375 1.375^2<2<1.4375^2 1.375<√2<1.4375 (1.375+1.4375)/2=1.40625 1.40625^2<2<1.4375^2 1.40625<√2<1.4375 (1.40625+1.4375)/2=1.421875 1.40625^2<2<1.421875^2 1.40625<√2<1.421875 (1.40625+1.421875)/2=1.4140625 1.4140625^2<2<1.421875^2 1.4140625<√2<1.421875 (1.4140625+1.421875)/2=1.41796875 1.4140625^2<2<1.41796875^2 1.4140625<√2<1.41796875 √2=1.41

Answer 2

(1.25+1.5)=1.375 1.375^2<2<1.5^2 1.375<√2<1.5 (1.375+1.5)/2=1.4375 1.375^2<2<1.4375^2 1.375<√2<1.4375 (1.375+1.4375)/2=1.40625 1.40625^2<2<1.4375^2 1.40625<√2<1.4375 (1.40625+1.4375)/2=1.421875 1.40625^2<2<1.421875^2 1.40625<√2<1.421875 (1.40625+1.421875)/2=1.4140625 1.4140625^2<2<1.421875^2 1.4140625<√2<1.421875 (1.4140625+1.421875)/2=1.41796875 1.4140625^2<2<1.41796875^2 1.4140625<√2<1.41796875 √2=1.41
谢谢楼主选我为最佳答案 感激不尽啊

Answer 3

解：(1.25+1.5)=1.375 1.375^2<2<1.5^2 1.375<√2<1.5 (1.375+1.5)/2=1.43751.375^2<2<1.4375^2 1.375<√2<1.4375 (1.375+1.4375)/2=1.40625 1.40625^2<2<1.4375^2 1.40625<√2<1.4375 (1.40625+1.4375)/2=1.421875 1.40625^2<2<1.421875^2 1.40625<√2<1.421875 (1.40625+1.421875)/2=1.4140625 1.4140625^2<2<1.421875^2 1.4140625<√2<1.421875 (1.4140625+1.421875)/2=1.41796875 1.4140625^2<2<1.41796875^2 1.4140625<√2<1.41796875 √2=1.41