English

Express the following matrices as the sum of a symmetric and a skew symmetric matrix: [351-1] - Mathematics

Advertisements
Advertisements

Question

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

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

Sum
Advertisements

Solution

to suppose, A = `[(3,5),(1, -1)],` A' =`[(3,1),(5, -1)]`

So, A `1/2` (A + A') + `1/2` (A - A')

Let, P = `1/2` (A + A') = `1/2 ([(3, 5),(1, -1)]) + ([(3, 1),(5, -1)])`

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

`= 1/2 [(6, 6), (6, -2)]`

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

and, `"P'" = [(3, 3), (3, -1)] = "P",`

Therefore, the matrix P is a symmetric matrix.

Then, Q = `1/2` (A - A') = `1/2  ([(3, 5),(1, -1)]) - ([(3, 1),(5, -1)])`

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

`= 1/2 [(0,4), (-4, 0)]`

`= [(0,2), (-2, 0)]`

and, Q' = `[(0,2), (-2, 0)]` = - Q,

Hence the matrix Q is a skew symmetric matrix.

So, A = P + Q

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

shaalaa.com
  Is there an error in this question or solution?
Chapter 3: Matrices - Exercise 3.3 [Page 89]

APPEARS IN

NCERT Mathematics Part 1 and 2 [English] Class 12
Chapter 3 Matrices
Exercise 3.3 | Q 10.1 | Page 89

Video TutorialsVIEW ALL [1]

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 is a skew symmetric matric of order 3, then prove that det A  = 0


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'


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'


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


Show that the matrix  A = `[(1,-1,5),(-1,2,1),(5,1,3)]` is a 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:

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


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

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


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


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 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)]`


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


If A and B are two skew-symmetric matrices of same order, then AB is symmetric matrix if ______.


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


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


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


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


If A is symmetric matrix, then B′AB is ______.


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


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


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?


If ax4 + bx3 + cx2 + dx + e = `|(2x, x - 1, x + 1),(x + 1, x^2 - x, x - 1),(x - 1, x + 1, 3x)|`, then the value of e is ______.


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 ______.


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?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×