मराठी

For the matrices A and B, verify that (AB)′ = B'A', where A = [(1),(–4),(3)], B = [(–1, 2, 1)]

Advertisements
Advertisements

प्रश्न

For the matrices A and B, verify that (AB)′ = B'A', where A = `[(1),(-4),(3)]`, B = `[(-1, 2, 1)]`

बेरीज
Advertisements

उत्तर

Given, A = `[(1),(-4),(3)]`, B = `[(-1, 2, 1)]`

So, AB = `[(1),(-4),(3)] xx [(-1, 2, 1)]`

= `[(1 xx (-1), 1 xx 2, 1 xx 1), (-4 xx (-1), -4 xx 2, -4 xx 1),(3 xx (-1), 3 xx 2, 3 xx 1)]`

= `[(-1, 2, 1), (4, -8, -4), (-3, 6, 3)]`

Now, (AB)' = `[(-1, 4, -3),(2, -8, 6), (1, -4, 3)]`   ...(i)

A' = `[(1, -4, 3)]` and B' = `[(-1),(2),(1)]`

Now, B'A' = `[(-1),(2),(1)] xx [(1, -4, 3)]`

= `[(-1 xx 1, -1 xx (-4), -1 xx 3),(2 xx 1, 2 xx (-4), 2 xx 3), (1 xx 1, 1 xx (-4), 1 xx 3)]`

= `[(-1, 4, -3),(2, -8, 6),(1, -4, 3)]`   ...(ii)

It is proved from the equation and that, (AB)' = B'A'

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 3: Matrices - EXERCISE 3.3 [पृष्ठ ६७]

APPEARS IN

एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
पाठ 3 Matrices
EXERCISE 3.3 | Q 5. (i) | पृष्ठ ६७

संबंधित प्रश्‍न

If A' = `[(3, 4),(-1, 2),(0, 1)]` and B = `[(-1, 2, 1),(1, 2, 3)]`, then verify that (A – B)' = A' – B'


If A' = `[(-2, 3),(1, 2)]` and B = `[(-1, 0),(1, 2)]`, then find (A + 2B)'


If A = `[(cos α, sin α), (-sin α, cos α)]`, then verify that  A' A = I


Express the following matrices as the sum of a symmetric and a skew symmetric matrix:

`[(3, 5),(1, -1)]`


Express the following matrices as the sum of a symmetric and a skew symmetric matrix:

`[(6, -2, 2),(-2, 3, -1),(2, -1, 3)]`


Show that all the diagonal elements of a skew symmetric matrix are zero.


if A =`((5,a),(b,0))` is symmetric matrix show that a = b


If A and B are symmetric matrices of the same order, write whether AB − BA is symmetric or skew-symmetric or neither of the two.


Write a square matrix which is both symmetric as well as skew-symmetric.


If \[A = \begin{bmatrix}1 & 2 \\ 0 & 3\end{bmatrix}\] is written as B + C, where B is a symmetric matrix and C is a skew-symmetric matrix, then B is equal to.


If A and B are symmetric matrices, then ABA is


If A and B are matrices of the same order, then ABT − BAT is a 


The matrix   \[A = \begin{bmatrix}1 & 0 & 0 \\ 0 & 2 & 0 \\ 0 & 0 & 4\end{bmatrix}\] is

 


If the matrix `((6,-"x"^2),(2"x"-15 , 10))` is symmetric, find the value of x.


Show that a matrix which is both symmetric and skew symmetric is a zero matrix.


Express the matrix A as the sum of a symmetric and a skew-symmetric matrix, where A = `[(2, 4, -6),(7, 3, 5),(1, -2, 4)]`


If A and B are symmetric matrices of the same order, then (AB′ –BA′) is a ______.


If A, B are square matrices of same order and B is a skew-symmetric matrix, show that A′BA is skew-symmetric.


The matrix `[(1, 0, 0),(0, 2, 0),(0, 0, 4)]` is a ______.


Sum of two skew-symmetric matrices is always ______ matrix.


If A is a symmetric matrix, then A3 is a ______  matrix.


If A and B are symmetric matrices, then AB – BA is a ______.


If A and B are symmetric matrices, then BA – 2AB is a ______.


If A and B are any two matrices of the same order, then (AB)′ = A′B′.


If A and B are symmetric matrices of the same order, then ____________.


If A and B are symmetric matrices of the same order, then ____________.


If A = `[(3, "x" - 1),(2"x" + 3, "x" + 2)]` is a symmetric matrix, then x = ____________.


If A is any square matrix, then which of the following is skew-symmetric?


The diagonal elements of a skew symmetric matrix are ____________.


Let A and B be and two 3 × 3 matrices. If A is symmetric and B is skewsymmetric, then the matrix AB – BA is ______.


If `[(2, 0),(5, 4)]` = P + Q, where P is symmetric, and Q is a skew-symmetric matrix, then Q is equal to ______.


Number of symmetric matrices of order 3 × 3 with each entry 1 or – 1 is ______.


A square matrix \[A=[a_{ij}]_{n\times n}\] is skew-symmetric when which condition holds?


Why does multiplying \[A+A^T\] by \[\frac{1}{2}\] not change its symmetric property?


For \[B=\begin{bmatrix}2&-2&-4\\-1&3&4\\1&-2&-3\end{bmatrix}\], what is its skew-symmetric part \[Q=\frac{1}{2}(B-B^T)\]?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×