हिंदी

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)]`

योग
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
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Matrices - EXERCISE 3.3 [पृष्ठ ६७]

APPEARS IN

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

संबंधित प्रश्न

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 = `[(0),(1),(2)]`, B = `[(1, 5, 7)]`


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


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


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


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.


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:

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


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


If A and B are symmetric matrices, then ABA is


If A = [aij] is a square matrix of even order such that aij = i2 − j2, then 


The matrix  \[A = \begin{bmatrix}0 & - 5 & 8 \\ 5 & 0 & 12 \\ - 8 & - 12 & 0\end{bmatrix}\] is a 

 

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


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


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


If A = `[(cosalpha, sinalpha),(-sinalpha, cosalpha)]`, and A–1 = A′, find value of α


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.


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


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


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


If A = [aij] is a skew-symmetric matrix of order n, then ______.


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


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×