Two Plus Two Older Archives

Two Plus Two Older Archives (http://archives2.twoplustwo.com/index.php)
-   Science, Math, and Philosophy (http://archives2.twoplustwo.com/forumdisplay.php?f=45)
-   -   Math/ imaginary numbers (http://archives2.twoplustwo.com/showthread.php?t=393538)

allintuit 12-07-2005 04:07 PM

Math/ imaginary numbers
 
How can you evaluate (-4)^(3/2)? I have two possible answers, which seems unusual.

sweetjazz 12-07-2005 04:12 PM

Re: Math/ imaginary numbers
 
Nothing unusual here -- every complex number (besides zero) has two square roots. Since (-4)^3 = -64, the two values of (-4)^(3/2) are 8i and -8i.

It's nothing different than the fact that there are two square roots of 2: 2^(1/2) and -(2^(1/2)). When taking the square root of a positive real number, we can always pick the positive one if we like. When taking the square root of a complex number, neither one is positive or negative, so each square root is as good as the other.

Hope that helps.

henrikrh 12-07-2005 04:36 PM

Re: Math/ imaginary numbers
 
DAmn thought I was in OOT and this was gonna be about Calvin and Hobbes.

Eleventeen and twentytwelve, you know.


All times are GMT -4. The time now is 09:12 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.