हिंदी

Find the Inverse by Using Elementary Row Transformations: [ 5 2 2 1 ] - Mathematics

Advertisements
Advertisements

प्रश्न

Find the inverse by using elementary row transformations:

\[\begin{bmatrix}5 & 2 \\ 2 & 1\end{bmatrix}\]

योग

उत्तर

\[A = \begin{bmatrix} 5 & 2\\2 & 1 \end{bmatrix}\]
We know
\[A = IA\]
\[ \Rightarrow \begin{bmatrix} 5 & 2\\2 & 1 \end{bmatrix} = \begin{bmatrix} 1 & 0\\0 & 1 \end{bmatrix} A\]
\[ \Rightarrow \begin{bmatrix} 5 - 4 & 2 - 2\\ 2 & 1 \end{bmatrix} = \begin{bmatrix} 1 - 0 & 0 - 2\\ 0 & 1 \end{bmatrix}A [\text{ Applying }R_1 \to R_1 - 2 R_2 ]\]
\[ \Rightarrow \begin{bmatrix} 1 & 0\\2 & 1 \end{bmatrix} = \begin{bmatrix} 1 & - 2\\ 0 & 1 \end{bmatrix} A \]
\[ \Rightarrow \begin{bmatrix} 1 & 0\\2 - 2 & 1 \end{bmatrix} = \begin{bmatrix} 1 & - 2\\ 0 - 2 & 1 + 4 \end{bmatrix} A [\text{ Applying }R_2 \to R_2 - 2 R_1 ]\]
\[ \Rightarrow \begin{bmatrix} 1 & 0\\0 & 1 \end{bmatrix} = \begin{bmatrix} 1 & - 2\\ - 2 & 5 \end{bmatrix}A\]
\[ \Rightarrow A^{- 1} = \begin{bmatrix} 1 & - 2\\ - 2 & 5 \end{bmatrix}\]

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 7: Adjoint and Inverse of a Matrix - Exercise 7.2 [पृष्ठ ३४]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 12
अध्याय 7 Adjoint and Inverse of a Matrix
Exercise 7.2 | Q 2 | पृष्ठ ३४

संबंधित प्रश्न

Find the adjoint of the matrices.

`[(1,-1,2),(2,3,5),(-2,0,1)]`


Find the inverse of the matrices (if it exists).

`[(1,0,0),(3,3,0),(5,2,-1)]`


If A = `[(3,1),(-1,2)]` show that A2 – 5A + 7I = O. Hence, find A–1.


If `A^(-1) =[(3,-1,1),(-15,6,-5),(5,-2,2)]` and `B = [(1,2,-2),(-1,3,0),(0,-2,1)]`  find  `(AB)^(-1)`


Let A = `[(1, sin theta, 1),(-sin theta,1,sin 1),(-1, -sin theta, 1)]` where 0 ≤ θ≤ 2π, then ______.


Find the adjoint of the following matrix:
\[\begin{bmatrix}a & b \\ c & d\end{bmatrix}\]

Verify that (adj A) A = |A| I = A (adj A) for the above matrix.

Find the adjoint of the following matrix:
\[\begin{bmatrix}\cos \alpha & \sin \alpha \\ \sin \alpha & \cos \alpha\end{bmatrix}\]

Verify that (adj A) A = |A| I = A (adj A) for the above matrix.

Find the adjoint of the following matrix:

\[\begin{bmatrix}1 & \tan \alpha/2 \\ - \tan \alpha/2 & 1\end{bmatrix}\]
Verify that (adj A) A = |A| I = A (adj A) for the above matrix.

If  \[A = \begin{bmatrix}- 4 & - 3 & - 3 \\ 1 & 0 & 1 \\ 4 & 4 & 3\end{bmatrix}\], show that adj A = A.


If \[A = \begin{bmatrix}- 1 & - 2 & - 2 \\ 2 & 1 & - 2 \\ 2 & - 2 & 1\end{bmatrix}\] , show that adj A = 3AT.


Find A (adj A) for the matrix  \[A = \begin{bmatrix}1 & - 2 & 3 \\ 0 & 2 & - 1 \\ - 4 & 5 & 2\end{bmatrix} .\]


Find the inverse of the following matrix.

\[\begin{bmatrix}1 & 2 & 5 \\ 1 & - 1 & - 1 \\ 2 & 3 & - 1\end{bmatrix}\]

Find the inverse of the following matrix.

\[\begin{bmatrix}0 & 0 & - 1 \\ 3 & 4 & 5 \\ - 2 & - 4 & - 7\end{bmatrix}\]

Find the inverse of the following matrix.

\[\begin{bmatrix}1 & 0 & 0 \\ 0 & \cos \alpha & \sin \alpha \\ 0 & \sin \alpha & - \cos \alpha\end{bmatrix}\]

Find the inverse of the following matrix and verify that \[A^{- 1} A = I_3\]

\[\begin{bmatrix}1 & 3 & 3 \\ 1 & 4 & 3 \\ 1 & 3 & 4\end{bmatrix}\]

For the following pair of matrix verify that \[\left( AB \right)^{- 1} = B^{- 1} A^{- 1} :\]

\[A = \begin{bmatrix}2 & 1 \\ 5 & 3\end{bmatrix}\text{ and }B \begin{bmatrix}4 & 5 \\ 3 & 4\end{bmatrix}\]


If \[A = \begin{bmatrix}3 & 1 \\ - 1 & 2\end{bmatrix}\], show that 

\[A^2 - 5A + 7I = O\].  Hence, find A−1.

If \[A = \begin{bmatrix}2 & - 1 & 1 \\ - 1 & 2 & - 1 \\ 1 & - 1 & 2\end{bmatrix}\].
Verify that \[A^3 - 6 A^2 + 9A - 4I = O\]  and hence find A−1.

Find the inverse by using elementary row transformations:

\[\begin{bmatrix}2 & 5 \\ 1 & 3\end{bmatrix}\]


Find the inverse by using elementary row transformations:

\[\begin{bmatrix}1 & 3 & - 2 \\ - 3 & 0 & - 1 \\ 2 & 1 & 0\end{bmatrix}\]


If A is symmetric matrix, write whether AT is symmetric or skew-symmetric.


If A is an invertible matrix such that |A−1| = 2, find the value of |A|.


If \[A = \begin{bmatrix}3 & 4 \\ 2 & 4\end{bmatrix}, B = \begin{bmatrix}- 2 & - 2 \\ 0 & - 1\end{bmatrix},\text{ then }\left( A + B \right)^{- 1} =\]


If B is a non-singular matrix and A is a square matrix, then det (B−1 AB) is equal to ___________ .


If A satisfies the equation \[x^3 - 5 x^2 + 4x + \lambda = 0\] then A-1 exists if _____________ .


If \[A = \begin{bmatrix}2 & 3 \\ 5 & - 2\end{bmatrix}\]  be such that \[A^{- 1} = kA\], then k equals ___________ .


If a matrix A is such that \[3A^3 + 2 A^2 + 5 A + I = 0,\text{ then }A^{- 1}\] equal to _______________ .


If x, y, z are non-zero real numbers, then the inverse of the matrix \[A = \begin{bmatrix}x & 0 & 0 \\ 0 & y & 0 \\ 0 & 0 & z\end{bmatrix}\], is _____________ .

Using matrix method, solve the following system of equations: 
x – 2y = 10, 2x + y + 3z = 8 and -2y + z = 7


If A and B are invertible matrices, then which of the following is not correct?


`("aA")^-1 = 1/"a"  "A"^-1`, where a is any real number and A is a square matrix.


Find the value of x for which the matrix A `= [(3 - "x", 2, 2),(2,4 - "x", 1),(-2,- 4,-1 - "x")]` is singular.


For matrix A = `[(2,5),(-11,7)]` (adj A)' is equal to:


If `abs((2"x", -1),(4,2)) = abs ((3,0),(2,1))` then x is ____________.


If A is a square matrix of order 3, |A′| = −3, then |AA′| = ______.


If A = `[(2, -3, 5),(3, 2, -4),(1, 1, -2)]`, find A–1. Use A–1 to solve the following system of equations 2x − 3y + 5z = 11, 3x + 2y – 4z = –5, x + y – 2z = –3


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×