
Math General Math Forum  For general math related discussion and news 
 LinkBack  Thread Tools  Display Modes 
September 11th, 2019, 07:37 AM  #1 
Newbie Joined: Sep 2019 From: Sri Lanka Posts: 1 Thanks: 0  What is this theory called?
$\displaystyle \sqrt{4}=2$ I was said that above equation is false. And also, $\displaystyle \sqrt{a^2}=\lefta\right$ $\displaystyle \mathrm{For}\:a\ge \:0\:\mathrm{rewrite\:}\:\sqrt{a^2}=\lefta\right \:\mathrm{\:as}\:\sqrt{a^2}=a$ $\displaystyle \mathrm{For}\:a<0\:\mathrm{rewrite\:}\:\sqrt{a^2}= \lefta\right\:\mathrm{\:as}\:\sqrt{a^2}=a$ What is this theory and where can I found more about this theory? Tnx. 
September 12th, 2019, 12:38 PM  #2 
Senior Member Joined: Jun 2019 From: USA Posts: 387 Thanks: 212 
I don't know about a theory, but every mathematical convention I have ever seen took √ to represent the principal square root, which is exactly what you have described (for positive, real numbers).


Tags 
called, theory 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
What is this called  Skykai  Math  6  January 13th, 2016 01:09 PM 
What's this math is called  Rossy  Algebra  5  January 17th, 2014 08:58 PM 
How is it called?  ricsi046  Linear Algebra  2  December 17th, 2013 02:50 PM 
what's this called?  srd  Algebra  7  April 23rd, 2013 12:37 AM 
what is this called?  tejolson  Algebra  1  December 27th, 2012 10:15 AM 