Maths

👨🏻‍🏫 學術台數學

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2010-01-01 2:36 am

Evaluate
[√(3+√5) + √(3-√5)]^2

without using any calulator.

Cheers~

更新1:

Sorry chanchiuhunh, your answer is wrong.

回答 (2)

用戶2053

2010-01-01 2:50 am

✔ 最佳答案

[√(3+√5) + √(3-√5)]^2

= (3+√5) + 2√(3+√5) √(3-√5) + (3-√5)

= 6 + 2√(3^2 - 5)

= 6 + 2√4

= 6 + 2*2

=10

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[匿名]

2010-01-01 2:42 am

[√(3+√5) + √(3-√5)]^2
= {/+√(3-√5)-/}2
=2*2
=4

2010-02-04 20:06:41 補充：
-_-,sorry,

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