Factorise (x−y)3+(y−z)3+(z−x)3 [3 MARKS]
Formula: 1 Mark Application: 2 Marks Let (x−y)=a,(y−z)=b,(z−x)=c ∵a+b+c=(x−y)+(y−z)+(z−x)=0
a+b+c=0⇒a3+b3+c3=3abc ∴(x−y)3+(y−z)3+(z−x)3=3(x−y)(y−z)(z−x)
Simplify :
(x-y) 3 + (y-z) 3 + (z-x) 3