Revision Notes for CBSE Class 12 Maths Chapter 3 (Matrices) - Free PDF Download
FAQs on Matrices Class 12 Notes CBSE Maths Chapter 3 (Free PDF Download)
1. What is the Transpose of a Matrix and its properties?
For a matrix X = [xij]mxn, we get its transpose by interchanging its rows with columns. The transpose matrix will be of order n x m and is denoted by a. So, the transpose of X is X’ or XT. We will clarify this with an example:
X = |1 2|
|3 4|
|5 6| then transpose of X, XT = |1 3 5|
|2 4 6|
The properties of a transpose are:
(X’)’ = X
(X + Y)’ = X’ + Y’
(XY)’ = Y’X’
(kX)’ = kX’
(XYZ)’ = Z’Y’X’
2. What are Invertible Matrices and Their Properties?
A square matrix X of order m is said to be invertible if there exists another square matrix Y (of the same order m) such that XY = YX = 1, then Y is called the inverse matrix of X and is represented by X-1. Let us see an example of the inverse of a matrix:
X =|2 3|
|1 2|
and Y = |2 -3|
|-1 2|
XY = |4 - 3 -6 + 6|
|2 - 2 -3 + 4|
|2 -3|
|-1 2| = 1
Below are listed a few of the properties of invertible matrices:
If Y is the inverse of X, then X is also an inverse of Y.
To be invertible, matrices need to be square matrices and must have the same order. That is why rectangular matrices are not invertible.
3. What do you mean by matrices?
Matrices are rectangular arrays of integers with rows and columns. Matrices are used to execute mathematical operations such as addition, multiplication, subtraction, and division. The numbers are referred to as matrix elements or entries. Matrices find their extensive usage in the domains of engineering, physics, economics, and statistics, as well as in many fields of mathematics. The size of the matrix is referred to as its order, and it is represented by rows and columns. Rows are always stated first in practice.
4. What do you mean by a scalar matrix?
A scalar matrix is a square matrix with a constant value as every element of its major diagonal and zeros for all other elements. A scalar matrix has all off-diagonal members equal to 0, and the values exhibited by all on-diagonal elements is 1. It is defined as a multiple of an identity matrix with any scalar quantity. It is a square matrix that exhibits the same number of rows and columns. To know more about matrices, you can download the Vedantu revision notes PDF of Chapter 3 free of cost from the website and app.
5. How can we utilise matrices in our day-to-day life?
Matrices are used to create graphs and statistics, as well as to conduct scientific investigations and research in a variety of disciplines. Matrices may also be used to represent real-world statistics such as population, infant mortality rate, and so on. Matrices are frequently used in engineering, physical problems, statistics, and economics, as well as many other domains related to mathematics. Multiplying matrices can provide rapid but accurate approximations to considerably more difficult calculations in many time-critical engineering applications.
6. What are the different types of matrices in Chapter 3 of Class 12 Maths?
Row matrices, column matrices, null matrices, square matrices, diagonal matrices, upper triangular matrices, lower triangular matrices, symmetric matrices, and asymmetric matrices are some of the several forms of matrices. All off-diagonal elements in a scalar matrix are equal to zero, but all non-diagonal elements are equal. Proper knowledge of these types and the ways to solve problems related to them is very crucial as they carry a significant weightage in the board’s paper.
7. Is multiplication of matrices distributive in nature?
As with real numbers, matrices may be distributed similarly. Check that each product of a matrix A has A on the left if the matrix A is distributed from the left! Matrix product requires that the entries belong to a semiring, but it is not necessary that the multiplication of the semiring's elements be commutative. The product is not commutative in general for matrices over fields; however, it is associative and distributive over matrix addition.