Last updated on August 26th, 2025
A non-singular matrix is a square matrix that has a non-zero determinant. This property plays an important role in linear algebra. It has many applications, such as transforming vector spaces, solving systems of equations, and performing various matrix operations.
A non-singular matrix has a non-zero determinant and is also an invertible matrix. The inverse of a matrix can be calculated only when its determinant is non-zero. For example,
A =
Non-singular if |A| = ad – bc 0
Characteristics |
Singular Matrix |
Non-singular matrix |
Determinant |
det(A) = 0 |
det(A) 0 |
Inverse |
A singular matrix is not invertible. |
Non-singular is invertible (A-1) |
Rank |
Rank is less than the order of the matrix |
Rank is equal to the order of the matrix |
Linear (in)dependent |
Dependent rows/columns |
Independent rows/columns |
System Ax = b |
A singular matrix may have either no solution or infinitely many solutions, but not a unique solution. |
For Ax = b, a non-singular matrix has exactly one unique solution. |
To find a non-singular matrix, we need to compute the determinant. If the determinant A is not equal to 0, then it's a non-singular matrix; if det(A) = 0, it will be singular. To find the determinant, we can do:
Row operations
Cofactor expansion
Rule of Sarrus (33 matrices)
Now compute the determinant
|A| = 2.9 – 0.5 = 18
As 18 0, A is non-singular.
To check whether a 22 matrix is non-singular, calculate its determinant using the formula det = ad – bc. If the result is non-zero, then the matrix is non-singular and therefore invertible.
For example:
Calculate: |A| = (43) – (12) = 12 – 2 = 10 0 A is non-singular.
A matrix is invertible only if its determinant is not zero. There are some methods to find the inverse, like the adjoint method or elementary row transformations.
Row reduction: To find the inverse of a matrix using row reduction, we transform the matrix into the identity matrix by applying row operations. At the same time, we also apply those operations to an identity matrix, which then becomes the inverse.
Calculate the determinant :
det(A) = (54) – (-32) = 20 + 6 = 26 0
Form the adjoint by swapping the positions of a and d, and changing the signs of b and c.
Divide by the determinant:
AA-1 = I
Rank defines the count of independent rows and columns in a matrix. This means none of the rows or columns can be written as a combination of the others. For a nn, non-singular matrix, all its columns and rows are independent. Its rank = n — means it's full rank.
This is a 22 matrix as det(A) 0, A is a non-singular also full rank rank = 2. If you reduce to row echelon form, you will get 2 non-zero rows, which confirms rank = 2.
Non-singular matrices play an important role in the fields of biology, art and design, architecture, and technology. Here are some of the real-life applications:
Students might make mistakes while dealing with non-singular matrices; this may lead to incorrect results. Knowing the mistake and solution can help them in solving the linear algebra computations.