求(1-1⼀2+1⼀4-1⼀6+1⼀8-1⼀10+……+1⼀48-1⼀50)*10的整数部分?

2025-02-24 02:47:04
推荐回答(3个)
回答1:

看不明白可以追问,求采纳,谢谢啦

回答2:

(1-1/2+1/4-1/6+1/8-1/10+……+1/48-1/50)*10
=(2-1+1/2-1/3+1/4-1/5+……+1/24-1/25)*5
=10-(1-1/2+1/3-1/4+1/5-……-1/24+1/25)*5
≈10-5ln(1+1)
=10-ln32
=10-3.47=6.53
正数的整数部分应该=向下取整=6
四舍五入取整=向上取整=7

回答3:

把括号里的看作等比数列: