English

If A = [(–1, 2, 3),(5, 7, 9),(–2, 1, 1)] and B = [(–4, 1, –5),(1, 2, 0),(1, 3, 1)], then verify that (A + B)' = A' + B'

Advertisements
Advertisements

Question

If A = `[(-1, 2, 3),(5, 7, 9),(-2, 1, 1)]` and B = `[(-4, 1, -5),(1, 2, 0),(1, 3, 1)]`, then verify that (A + B)' = A' + B'

Sum
Advertisements

Solution

Given, A = `[(-1, 2, 3),(5, 7, 9),(-2, 1, 1)]` and B = `[(-4, 1, -5),(1, 2, 0),(1, 3, 1)]` 

Then, (A + B) = A = `[(-1, 2, 3),(5, 7, 9),(-2, 1, 1)] + [(-4, 1, -5),(1, 2, 0),(1, 3, 1)]`

= `[(-1 -4, 2 + 1, 3 - 5),(5 + 1, 7 + 2, 9 + 0),(-2 + 1, 1 + 3, 1 + 1)]`

= `[(-5, 3, -2),(6, 9, 9),(-1, 4, 2)]`

Now, (A + B)' = `[(-5, 6, -1),(3, 9, 4),(-2, 9, 2)]`   ...(i)

 A' = `[(-1, 5, -2),(2, 7, 1),(3, 9, 1)]` and B' = `[(-4, 1, 1),(1, 2, 3),(-5, 0, 1)]`

Then,  A' + B' = `[(-1, 5, -2),(2, 7, 1),(3, 9, 1)] + [(-4, 1, 1),(1, 2, 3),(-5, 0, 1)]`

= `[(-1 - 4, 5 + 1, -2 + 1), (2 + 1, 7 + 2, 1 + 3), (3 - 5, 9 + 0, 1 + 1)]`

`[(-5, 6, -1),(3, 9, 4),(-2, 9, 2)]`   ...(ii)

Equations (i) and (ii) prove that,

(A + B)' = A' + B'

shaalaa.com
  Is there an error in this question or solution?
Chapter 3: Matrices - EXERCISE 3.3 [Page 66]

APPEARS IN

NCERT Mathematics Part 1 and 2 [English] Class 12
Chapter 3 Matrices
EXERCISE 3.3 | Q 2. (i) | Page 66

RELATED QUESTIONS

If A`((3,5),(7,9))`is written as A = P + Q, where P is a symmetric matrix and Q is skew symmetric matrix, then write the matrix P.

 


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


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


Show that the matrix  A = `[(0, 1, -1),(-1, 0, 1),(1, -1, 0)]` is a skew symmetric matrix.


For the matrix A = `[(1, 5),(6, 7)]`, verify that (A – A') is a skew symmetric matrix.


Find `1/2` (A + A') and `1/2` (A – A'), when A = `[(0, a, b),(-a, 0, c),(-b, -c, 0)]`


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

`[(3, 3, -1),(-2, -2, 1),(-4, -5, 2)]`


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

`[(1, 5),(-1, 2)]`


Show that the matrix B'AB is symmetric or skew symmetric according as A is symmetric or skew symmetric.


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


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 is a square matrix, then AA is a


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


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


Let A = `[(2, 3),(-1, 2)]`. Then show that A2 – 4A + 7I = O. Using this result calculate A5 also.


If A = `[(0, 1),(1, 1)]` and B = `[(0, -1),(1, 0)]`, show that (A + B)(A – B) ≠ A2 – B2 


Show that A′A and AA′ are both symmetric matrices for any matrix 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 ______.


The matrix `[(0, -5, 8),(5, 0, 12),(-8, -12, 0)]` is a ______.


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


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


If A is a skew-symmetric matrix, then A2 is a ______.


If A is skew-symmetric, then kA is a ______. (k is any scalar)


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


If P is of order 2 x 3 and Q is of order 3 x 2, then PQ is of order ____________.


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


If A, B are Symmetric matrices of same order, then AB – BA is a


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


The value of |A|, if A = `[(0, 2x - 1, sqrt(x)),(1 - 2x, 0, 2sqrt(x)),(-sqrt(x), -2sqrt(x), 0)]`, where x ∈ R+, is ______.


For what value of k the matrix `[(0, k),(-6, 0)]` is a skew symmetric matrix?


Which of the following is correct?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×