January 16th, 2017, 09:17 PM  #1 
Newbie Joined: Jan 2017 From: India Posts: 1 Thanks: 0  Maths Formula
how you can show (a+b)^2 = a^2 + 2ab + b^2

January 16th, 2017, 09:38 PM  #2 
Senior Member Joined: Aug 2012 Posts: 2,329 Thanks: 720  It's the standard multiplication of the two binomials $(a + b)(a + b)$. There's an acronym for this, FOIL: First, Outside, Inside, Last. So $(a + b)(a + b)$ $= a^2 + ba + ab + b^2 = a^2 + 2ab + b^2$ In other words: First, $a \times a$. Outside, $a \times b$. Inside, $b \times a$. Last: $b \times b$. Then collect terms. Another way to interpret this question is to write out a formal proof from axioms, carefully noting each use of the distributive law, commutative laws, associative laws, etc. Which interpretation are you asking? How to do it, or how to prove it from axioms? Last edited by Maschke; January 16th, 2017 at 09:44 PM. 

Tags 
formula, maths 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
I invented a new maths squaring formula  Mehul1201a  Elementary Math  4  January 10th, 2014 04:34 PM 
Maths videos from a maths teacher  eddiewoo  New Users  0  September 3rd, 2013 01:32 PM 
maths  apd2006  Advanced Statistics  4  May 25th, 2013 11:47 PM 
Maths dont know what a number ismaths ends in meaningless  bas  Number Theory  3  March 22nd, 2011 10:26 AM 
De Moivre's formula and Newton's binomial formula  agro  Probability and Statistics  3  August 27th, 2009 06:17 AM 