『Math』關於Function-----Completing the Square

👨🏻‍🏫 學術台數學

2006-10-16 12:55 am

Given that the sum of two positive nmber is 10.

Find the two nmbers so that the sum of their square is minimum.

我唔係太明白個問題問乜....
有無人可以教我計一計....最重要有Step~ THX A LOT!!

更新1:

Given that the sum of two positive number is 10. Find the two numbers so that the sum of their square is minimum. 我鍵盤的U 鍵壞壞地，成日打唔到個 U 字，搞到打錯左做nmbers，唔好意思！

回答 (2)

myisland8132

2006-10-16 1:22 am

✔ 最佳答案

let one number is x, then the other number is 10-x
sum of their square
=x^2+100-20x+x^2
=2x^2-20x+100
=2(x^2-10x+50)
differentiate x^2-10x+50
2x-10=0
x=5
so when x=5,the sum of their square is minimum
the two numbers are 5,5

👍 0 👎 0

用戶164535

2006-10-16 1:20 am

x+y=10
10=
1+9
2+8
3+7
4+6
5+5
1+81=82
4+64=70---
25+25=50is minimum

參考: myself

👍 0 👎 0

收錄日期: 2021-04-25 16:51:26
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061015000051KK03929

檢視 Wayback Machine 備份