मराठी

If A = [cosαsinα-sinαcosα] then verify that A' A = I - Mathematics

Advertisements
Advertisements

प्रश्न

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

बेरीज
Advertisements

उत्तर

Given, A = `[(cos  alpha, sin  alpha), (-sin  alpha, cos  alpha)]`

So, A' =`[(cos  alpha, -sin  alpha), (sin  alpha, cos  alpha)]`

Now, A' A = `[(cos  alpha, -sin  alpha), (sin  alpha, cos  alpha)] xx [(cos  alpha, sin  alpha), (-sin  alpha, cos  alpha)]`

`= [(cos^2 alpha+ sin^2 alpha, cos  alpha  sin  alpha - sin  alpha  cos  alpha),(sin  alpha  cos  alpha - cos  alpha  sin  alpha, sin^2 + cos^2 alpha)]`

`= [(1,0),(0,1)] = I         ...["Because"  sin^2 alpha + cos^2 alpha = 1]`

Hence, A' A = I

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 3: Matrices - Exercise 3.3 [पृष्ठ ८९]

APPEARS IN

एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
पाठ 3 Matrices
Exercise 3.3 | Q 6.1 | पृष्ठ ८९

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

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 = [(-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.


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

`[(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)]`


Show that the matrix B'AB is symmetric or skew symmetric according as A is symmetric or skew symmetric.


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


If a matrix A is both symmetric and skew-symmetric, then


If A is a square matrix, then AA is a


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  


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.


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


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 the matrix `[(0, "a", 3),(2, "b", -1),("c", 1, 0)]`, is a skew symmetric matrix, find the values of a, b and c.


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


If A is a symmetric matrix, then A3 is a ______  matrix.


If A and B are symmetric matrices, then BA – 2AB is a ______.


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?


The diagonal elements of a skew symmetric matrix are ____________.


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 ______.


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?


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×