StudentAidUnit 3: Matrices and Determinants — Exercise 3 Misc
10th Class Mathematics · Unit 3: Matrices and Determinants
1.Prove the identity (expansion and simplification): (a+b)^2 - (a-b)^2 = 4ab
Formula
Identity
(a+b)2-(a-b)2=4ab
Expand
(a+b)(a+b)-(a-b)(a-b) = (a2+2ab+b2)-(a2-2ab+b2)
Simplify
=(a2-a2)+(b2-b2)+(2ab+2ab)=0+0+4ab
Result
Conclusion
(a+b)2-(a-b)2=4ab