हिंदी

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

योग

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
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Matrices - Exercise 3.3 [पृष्ठ ८९]

APPEARS IN

एनसीईआरटी Mathematics [English] Class 12
अध्याय 3 Matrices
Exercise 3.3 | Q 6.1 | पृष्ठ ८९

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

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' [(3,4),(-1, 2),(0,1)] and B = [((-1,2,1),(1,2,3))]` 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]`


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


Find `1/2` (A + A')  and  `1/2` (A -A') When `A = [(0, a, b),(-a,0,c),(-b,-c,0)]`


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.


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?


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


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


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)]`


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.


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


If A is symmetric matrix, then B′AB is ______.


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


AA′ is always a symmetric matrix for any matrix 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 = [aij] is a skew-symmetric matrix of order n, then ______.


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 ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×