a^2+b^2=(a+b)^2-2ab a^3+b^3=?
Existential Member Joined May 26, 2010 Messages 620 Gender Undisclosed HSC N/A Feb 21, 2011 #1 a^2+b^2=(a+b)^2-2ab a^3+b^3=?
Bored Of Fail1 Banned Joined Feb 20, 2011 Messages 70 Gender Undisclosed HSC 2009 Feb 21, 2011 #2 use sum of cubes factorisation so (a+b)(a^2 -ab +b^2) = (a+b) ( ( a+b)^2 -2ab -ab ) = ( a+b) ( (a+b)^2 -3ab ) etc, then sub in values for a+b and ab
use sum of cubes factorisation so (a+b)(a^2 -ab +b^2) = (a+b) ( ( a+b)^2 -2ab -ab ) = ( a+b) ( (a+b)^2 -3ab ) etc, then sub in values for a+b and ab
Existential Member Joined May 26, 2010 Messages 620 Gender Undisclosed HSC N/A Feb 21, 2011 #3 so the simplification is (a+b)((a+b)^2-3ab). thankyou.