KCET2009MathematicsMatrices
If A and B are square matrices of the same order such that (A+B)(A-B)=A²-B² , then (A B A⁻¹ )² is equal to
Options
- AB ²
- BI
- CA ² ~B ²
- DA ²
Correct answer
A. B ²
Step-by-step solution
Given, (A+B)(A-B)=A²-B² A²-A B+B A-B²=A²-B² AB = BA Now, ( ABA ⁻¹ )²= ( BAA ⁻¹ )²= B ²