若A=πr²/6 及 L=πr/3 ,試求以A表示L。
A L=3A/3
B L=±√2Aπ/3
C L=±√3Aπ/2
D L=±√2A/3π
E L =±√3A/2π
請寫步驟!
maths~~~
2007-11-26 7:19 am
回答 (1)
2007-11-26 7:30 am
✔ 最佳答案
A = πr²/6 6A = πr²
6A/π = r²
r = ±√(6A/π)
so,
L
= πr/3
= (π/3)r
= (π/3)[±√(6A/π)]
= ±√[(6A/π)(π/3)²]
= ±√[(6A/π)(π²/9)]
= ±√(2Aπ/3)
= B
收錄日期: 2021-04-13 14:34:53
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https://hk.answers.yahoo.com/question/index?qid=20071125000051KK05717