A square matrix is a matrix with the same number of rows and columns. It has the form of n x n where n is the number of rows and columns. Square matrices are used in various operations such as finding determinants and solving systems of linear equations.
Class 12 Maths Chapter 3 on Determinants covers square arrays of numbers used to solve linear equations. Topics include properties of determinants calculation of 2×2 and 3×3 determinants cofactor expansion adjoint method Cramer’s rule and applications in finding areas of triangles and solving linear systems. Determinants are essential in algebra and geometry.
Share
Given that A is a square matrix and A² = A, we must reduce (I + A)² – 3A.
Step 1: Expand (I + A)²
(I + A)² = I² + 2IA + A²
Given that I² = I and A² = A, we get:
(I + A)² = I + 2A + A
(I + A)² = I + 3A
Step 2: Subtract 3A
Substitute this back into the expression:
(I + A)² – 3A = (I + 3A) – 3A
(I + A)² – 3A = I
Click here for more:
https://www.tiwariacademy.com/ncert-solutions/class-12/maths/#chapter-4