Algebra för Ma1A: Skillnad mellan sidversioner
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Rad 9: | Rad 9: | ||
For example, | For example, | ||
: | : <math> 62^2 = 37 \cdot 100 + 12^2 = 3844 </math> | ||
: | : | ||
: 44^2 = 19 \cdot 100 + 6^2 = 1936 | : 44^2 = 19 \cdot 100 + 6^2 = 1936 |
Versionen från 1 oktober 2014 kl. 21.20
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Från Quora:
Wu's Squaring Trick, named after the famous Scott Wu, is a technique used to quickly square numbers over 25 in your head. It uses the identity
- n2 = (n-25) \cdot 100 + (n-50)2
For example,
- [math]\displaystyle{ 62^2 = 37 \cdot 100 + 12^2 = 3844 }[/math]
- 44^2 = 19 \cdot 100 + 6^2 = 1936
- 77^2 = 52 \cdot 100 + 27^2 = 5929
These mental computations can be done very quickly with just a little practice, so amaze your friends with how fast you can square two digit numbers!