Skip to content

Matrix Properties

Easymathematics

The trace of a square matrix A is defined as the sum of its diagonal elements. If A = [[1, 2, 3], [4, 5, 6], [7, 8, 9]], then tr(A) equals

Select the correct option:

🔒 Solution Hidden from View

Submit your answer to unlock the detailed step-by-step solution.

More matrices and determinants Practice Questions

MediumJEE_MAIN

If A and B are symmetric matrices of the same order, then AB is symmetric if

View Solution→
HardJEE_MAIN

If A is a skew-symmetric matrix of odd order, then |A| equals

View Solution→
MediumJEE_ADVANCED

The area of the triangle with vertices at the points (1, 2), (4, 6) and (7, 2) in the coordinate pla...

View Solution→
HardJEE_ADVANCED

Let A be the two by two matrix with rows (2, 1) and (1, 2); using the Cayley-Hamilton theorem, the m...

View Solution→
HardJEE_ADVANCED

For any skew-symmetric matrix of odd order, the determinant always takes a fixed value; the determin...

View Solution→
HardJEE_ADVANCED

The homogeneous system of equations with coefficient matrix rows (1, 2, 3), (2, k, 6) and (1, 1, 1) ...

View Solution→
EasyJEE_ADVANCED

The value of the real parameter k for which the matrix with rows (k, 2, 3), (2, k, 1) and (3, 1, k) ...

View Solution→
EasyJEE_ADVANCED

If A and B are square matrices of order 3 with det(A) = 3 and det(B) = -2, then the determinant of t...

View Solution→
MediumJEE_ADVANCED

A square matrix A is called idempotent when it satisfies A squared equal to A; for such a matrix the...

View Solution→
MediumJEE_ADVANCED

If A is a square matrix of order 2 with trace equal to 5 and determinant equal to 6, then the sum of...

View Solution→
MediumJEE_ADVANCED

A square matrix A is nilpotent if some positive integer power of A equals the zero matrix; the deter...

View Solution→
MediumJEE_ADVANCED

Applying the property that adding a multiple of one row to another leaves a determinant unchanged, t...

View Solution→

Browse all matrices and determinants questions →

About This Question

Subject
mathematics
Chapter
matrices and determinants
Topic
matrix properties
Difficulty
Easy
Year
2025
Tags
MatricesTraceDiagonal Elements

Solution

Correct Answer:

15

  1. Identify Diagonals: In a square matrix, the diagonal elements are those where the row index equals the column index ().
  2. Identify Elements in A: The main diagonal elements are and .
  3. Calculation:
    • .
  4. Result: The trace is 15.

This easy difficulty mathematics question is from the chapter matrices and determinants, covering the topic of matrix properties. It appeared in the 2025 exam.

Looking for more practice? Explore all mathematics questions or browse matrices and determinants questions on RankGuru.