English

Express the matrix [2311-12412] as the sum of a symmetric and a skew-symmetric matrix.

Advertisements
Advertisements

Question

Express the matrix `[(2, 3, 1),(1, -1, 2),(4, 1, 2)]` as the sum of a symmetric and a skew-symmetric matrix.

Sum
Advertisements

Solution

We have, A = `[(2, 3, 1),(1, -1, 2),(4, 1, 2)]` 

We know that A = `("A" + "A'")/2 + ("A" - "A'")/2`

Where `("A" + "A'")/2` is symmetric and `("A" - "A'")/2` is skew-symmetric

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

Now, `("A" + "A'")/2 = ([(2, 3, 1),(1, -1, 2),(4, 1, 2)] + [(2, 1, 4),(3, -1, 1),(1, 2, 2)])/2`

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

= `[(2, 2, 5/2),(2, -1, 3/2),(5/2, 3/2, 2)]`

And `("A" - "A'")/2 = ([(2, 3, 1),(1, -1, 2),(4, 1, 2)] - [(2, 1, 4),(3, -1, 1),(1, 2, 2)])/2`

= `1/2 [(0, 2, -3),(-2, 0, 1),(3, -1, 0)]`

= `[(0,1, (-3)/2),(-1, 0, 1/2),(3/2, (-1)/2, 0)]`

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

= `[(2, 2, 5/2),(2, -1, 3/2),(5/2, 3/2, 2)] + [(0, 1, (-3)/2),(-1, 0, 1/2),(3/2, 1/2, 0)]`

shaalaa.com
  Is there an error in this question or solution?
Chapter 3: Matrices - Exercise [Page 59]

APPEARS IN

NCERT Exemplar Mathematics Exemplar [English] Class 12
Chapter 3 Matrices
Exercise | Q 52 | Page 59

RELATED QUESTIONS

Matrix A = `[(0,2b,-2),(3,1,3),(3a,3,-1)]`is given to be symmetric, find values of a and b


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'


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


For the matrices A and B, verify that (AB)′ = B'A' where A = `[(0),(1),(2)]`, B = `[(1, 5, 7)]`


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


For the matrix A = `[(1, 5),(6, 7)]` verify that (A + A') is a 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, 5),(1, -1)]`


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 the matrix A is both symmetric and skew symmetric, then ______.


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.


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 matrix A is both symmetric and skew-symmetric, then


If A is a square matrix, then AA is a


If A and B are symmetric matrices, then ABA is


If A and B are two matrices of order 3 × m and 3 × n respectively and m = n, then the order of 5A − 2B is 


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


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


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.


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 is symmetric matrix, then B′AB is ______.


If each of the three matrices of the same order are symmetric, then their sum is a symmetric matrix.


AA′ is always a symmetric matrix for any matrix A.


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


If A `= [(6,8,5),(4,2,3),(9,7,1)]` is the sum of a symmetric matrix B and skew-symmetric matrix C, then B is ____________.


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


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


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×