मराठी

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

Advertisements
Advertisements

प्रश्न

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

बेरीज
Advertisements

उत्तर

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

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

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

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

= `[(1, 0),(0, 1)]` = I   ...[∵ sin2 α + cos2 α = 1]

Hence, A' A = I

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 3: Matrices - EXERCISE 3.3 [पृष्ठ ६७]

APPEARS IN

एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
पाठ 3 Matrices
EXERCISE 3.3 | Q 6. (i) | पृष्ठ ६७

संबंधित प्रश्‍न

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 = `[(1),(-4),(3)]`, B = `[(-1, 2, 1)]`


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


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


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.


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


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

 

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)]`


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


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 ____________.


The diagonal elements of a skew symmetric matrix are ____________.


If A, B are Symmetric matrices of same order, then AB – BA is a


Let A and B be and two 3 × 3 matrices. If A is symmetric and B is skewsymmetric, then the matrix AB – BA 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 ______.


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


Which of the following is correct?


A square matrix \[A=[a_{ij}]_{n\times n}\] is skew-symmetric when which condition holds?


Which transpose property justifies the step \[(A+A^T)^T=A^T+(A^T)^T\]?


For \[B=\begin{bmatrix}2&-2&-4\\-1&3&4\\1&-2&-3\end{bmatrix}\], what is its skew-symmetric part \[Q=\frac{1}{2}(B-B^T)\]?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×