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.
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)]`
APPEARS IN
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 = `[(-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'
For the matrices A and B, verify that (AB)′ = B'A' where A = `[(0),(1),(2)]`, B = `[(1, 5, 7)]`
Show that the matrix A = `[(1, -1, 5),(-1, 2, 1),(5, 1, 3)]` is a symmetric matrix.
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:
`[(1, 5),(-1, 2)]`
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 is a square matrix, then AA is a
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 \[A = \begin{bmatrix}0 & - 5 & 8 \\ 5 & 0 & 12 \\ - 8 & - 12 & 0\end{bmatrix}\] is a
The matrix \[A = \begin{bmatrix}1 & 0 & 0 \\ 0 & 2 & 0 \\ 0 & 0 & 4\end{bmatrix}\] is
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 = `[(0, 1),(1, 1)]` and B = `[(0, -1),(1, 0)]`, show that (A + B)(A – B) ≠ A2 – B2
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 `[(0, -5, 8),(5, 0, 12),(-8, -12, 0)]` is a ______.
Sum of two skew-symmetric matrices is always ______ matrix.
If A is a symmetric matrix, then A3 is a ______ matrix.
If A is symmetric matrix, then B′AB is ______.
If A and B are symmetric matrices of same order, then AB is symmetric if and only if ______.
If A and B are any two matrices of the same order, then (AB)′ = A′B′.
If A is skew-symmetric matrix, then A2 is a symmetric matrix.
If A, B are Symmetric matrices of same order, then AB – BA is a
If A = [aij] is a skew-symmetric matrix of order n, then ______.
Let A = `[(2, 3),(a, 0)]`, a ∈ R be written as P + Q where P is a symmetric matrix and Q is skew-symmetric matrix. If det(Q) = 9, then the modulus of the sum of all possible values of determinant of P is equal to ______.
If `[(2, 0),(5, 4)]` = P + Q, where P is symmetric, and Q is a skew-symmetric matrix, then Q is equal to ______.
What must be true of every diagonal element of a skew-symmetric matrix?
If \[C=A-A^T\] for a square matrix \[A\], what is \[C^T\]?
Which transpose property justifies the step \[(A+A^T)^T=A^T+(A^T)^T\]?
How many decompositions of a square matrix into a symmetric part and a skew-symmetric part are possible?
