請問 400 的開方答案是多少 ?
回答 (7)
2007-04-18 8:58 pm
✔ 最佳答案
√400=(400)1/2
=20
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"√"即是二分之一次方,"3√"即是三分之一次方,如此類推
2007-04-19 16:42:17 補充：
-20是錯的!!!!請看看一條公式:『當 ax²＋bx＋c = 0x =[ -b±√(b² - 4ac)]÷2a,【"±"這個符號即是加或減】』這是中四數學的第一課的一條公式留意那個"±",放在"√"前面試想想,如果將一個數開方後是會將那個數分為正數和負數那個"±"豈不是很多餘?就是因為開方後只會是正數,所以才需要在這公式上用上"±"!!!
2007-04-18 9:47 pm
the square root of 400 = +20 or -20
so, all the previous answers are not complete.
This is very basic! If you don't have square root function, you can still use power function to carry out square root operation.
400 ^ 0.5 = square root of 400 = +20 or -20
so, all the previous answers are not complete.
This is very basic! If you don't have square root function, you can still use power function to carry out square root operation.
400 ^ 0.5 = square root of 400 = +20 or -20
2007-04-18 8:59 pm
The square root of 400 is 20
2007-04-18 8:57 pm
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原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070418000051KK01191