मराठी

For the matrices A and B, verify that (AB)′ = B'A' where A=[1-43],B=[-1,2 1] - Mathematics

Advertisements
Advertisements

प्रश्न

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

बेरीज
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
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 3: Matrices - Exercise 3.3 [पृष्ठ ८८]

APPEARS IN

एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
पाठ 3 Matrices
Exercise 3.3 | Q 5.1 | पृष्ठ ८८

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 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)'


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


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


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.


Show that the matrix  A = `[(0,1,-1),(-1,0,1),(1,-1,0)]` 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:

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


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)]`


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

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


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 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 \[A = \begin{bmatrix}1 & 2 \\ 0 & 3\end{bmatrix}\] is written as B + C, where B is a symmetric matrix and C is a skew-symmetric matrix, then B is equal to.


For what value of x, is the matrix \[A = \begin{bmatrix}0 & 1 & - 2 \\ - 1 & 0 & 3 \\ x & - 3 & 0\end{bmatrix}\] a skew-symmetric matrix?


The matrix \[\begin{bmatrix}0 & 5 & - 7 \\ - 5 & 0 & 11 \\ 7 & - 11 & 0\end{bmatrix}\] is


If A and B are symmetric matrices, then ABA is


If \[A = \begin{bmatrix}2 & 0 & - 3 \\ 4 & 3 & 1 \\ - 5 & 7 & 2\end{bmatrix}\]  is expressed as the sum of a symmetric and skew-symmetric matrix, then the symmetric matrix 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 


The matrix   \[A = \begin{bmatrix}1 & 0 & 0 \\ 0 & 2 & 0 \\ 0 & 0 & 4\end{bmatrix}\] is

 


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


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)]`


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 = `[(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 = `[(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 `[(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 ______.


______ matrix is both symmetric and skew-symmetric matrix.


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


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 A and B are symmetric matrices of same order, then AB is symmetric if and only if ______.


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


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 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 is any square matrix, then which of the following is skew-symmetric?


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 ____________.


The diagonal elements of a skew symmetric matrix are ____________.


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 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 ______.


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


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×