數學一問~急~~~ - Ans.fyi 參考答案

數學一問~急~~~

用戶179997

2006-12-20 4:21 am

............. ＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
...........／................＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
.........／.............／.............＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
........／...........／...........／...........＿＿＿＿＿＿＿＿＿＿＿＿＿＿　　= 2
＿ .／ a+.....／ a+.....／ a+.....／ a+ ……
... V...........V.............V...............V

求a的值
答案加詳解plz
ps:上面嗰啲全部係開方號，後面六點即係不斷重複

更新1:

請問　x² = a+x　點黎架 x² = a+x 之後 x = √(a+x) 我都明但係點解又會 = √(a+√(a+x) 又 =√(a+√(a+√(a + ... 嘅????

回答 (2)

Amby

2006-12-20 4:38 am

✔ 最佳答案

............. ＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
...........／................＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
.........／.............／.............＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿ = 2
........／...........／...........／...........＿＿＿＿＿＿＿＿＿＿＿＿＿＿　　
＿ .／ a+.....／ a+.....／ a+.....／ a+ ……
... V...........V....... ......V............. ..V
Consider the equation x² = a+x
x = √(a+x)
= √(a+√(a+x)
=√(a+√(a+√(a + ...

SO
............. ＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
...........／................＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
.........／.............／.............＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
........／...........／...........／...........＿＿＿＿＿＿＿＿＿＿＿＿＿＿　　
＿ .／ a+.....／ a+.....／ a+.....／ a+ ……
... V...........V....... ......V............. ..V
is the solution of x² = a+x
x² - x - a = 0
x = [1+√(1+4a)]/2 = 2
1+√(1+4a) = 4
√(1+4a) = 3
1+4a = 9
4a = 8
a = 2

2006-12-19 20:38:45 補充：
唔信可以用calculator計吓

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[匿名]

2006-12-23 4:07 am

i don't know

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