हिंदी

Find the Inverse by Using Elementary Row Transformations: ⎡ ⎢ ⎣ 0 1 2 1 2 3 3 1 1 ⎤ ⎥ ⎦ - Mathematics

Advertisements
Advertisements

प्रश्न

Find the inverse by using elementary row transformations:

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

योग

उत्तर

\[A = \begin{bmatrix}0 & 1 & 2 \\ 1 & 2 & 3 \\ 3 & 1 & 1\end{bmatrix}\]
We know
\[A = IA \]
\[ \Rightarrow \begin{bmatrix}0 & 1 & 2 \\ 1 & 2 & 3 \\ 3 & 1 & 1\end{bmatrix} = \begin{bmatrix}1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1\end{bmatrix} A\]
\[ \Rightarrow \begin{bmatrix}0 & 1 & 2 \\ - 2 & 1 & 2 \\ 3 & 1 & 1\end{bmatrix} = \begin{bmatrix}1 & 0 & 0 \\ 0 & 1 & - 1 \\ 0 & 0 & 1\end{bmatrix} A \left[\text{ Applying }R_2 \to R_2 - R_3 \right]\]
\[ \Rightarrow \begin{bmatrix}- 3 & 0 & 1 \\ - 2 & 1 & 2 \\ 3 & 1 & 1\end{bmatrix} = \begin{bmatrix}1 & 0 & - 1 \\ 0 & 1 & - 1 \\ 0 & 0 & 1\end{bmatrix} A \left[\text{ Applying }R_1 \to R_1 - R_3 \right]\]
\[ \Rightarrow \begin{bmatrix}- 3 & 0 & 1 \\ - 2 & 1 & 2 \\ 0 & 1 & 2\end{bmatrix} = \begin{bmatrix}1 & 0 & - 1 \\ 0 & 1 & - 1 \\ 1 & 0 & 0\end{bmatrix} A \left[\text{ Applying }R_3 \to R_3 + R_1 \right]\]
\[ \Rightarrow \begin{bmatrix}- 3 & 0 & 1 \\ 0 & 3 & 4 \\ 0 & 1 & 2\end{bmatrix} = \begin{bmatrix}1 & 0 & - 1 \\ - 2 & 3 & - 1 \\ 1 & 0 & 0\end{bmatrix} A \left[\text{ Applying }R_2 \to 3 R_2 - 2 R_1 \right]\]
\[ \Rightarrow \begin{bmatrix}- 3 & 0 & 1 \\ 0 & 3 & 4 \\ 0 & - 2 & - 2\end{bmatrix} = \begin{bmatrix}1 & 0 & - 1 \\ - 2 & 3 & - 1 \\ 3 & - 3 & 1\end{bmatrix} A \left[\text{ Applying }R_3 \to R_3 - R_2 \right]\]
\[ \Rightarrow \begin{bmatrix}- 3 & 0 & 1 \\ 0 & 3 & 4 \\ 0 & 1 & 1\end{bmatrix} = \begin{bmatrix}1 & 0 & - 1 \\ - 2 & 3 & - 1 \\ \frac{- 3}{2} & \frac{3}{2} & \frac{- 1}{2}\end{bmatrix} A \left[\text{ Applying }R_3 \to - \frac{1}{2} R_3 \right]\]
\[ \Rightarrow \begin{bmatrix}- 3 & 0 & 1 \\ 0 & - 1 & 0 \\ 0 & 1 & 1\end{bmatrix} = \begin{bmatrix}1 & 0 & - 1 \\ 4 & - 3 & 1 \\ \frac{- 3}{2} & \frac{3}{2} & \frac{- 1}{2}\end{bmatrix} A \left[ \text{ Applying }R_2 \to R_2 - 4 R_3 \right]\]
\[ \Rightarrow \begin{bmatrix}- 3 & 0 & 1 \\ 0 & - 1 & 0 \\ 0 & 0 & 1\end{bmatrix} = \begin{bmatrix}1 & 0 & - 1 \\ 4 & - 3 & 1 \\ \frac{5}{2} & \frac{- 3}{2} & \frac{1}{2}\end{bmatrix} A \left[ \text{ Applying }R_3 \to R_3 + R_2 \right]\]
\[ \Rightarrow \begin{bmatrix}- 3 & 0 & 0 \\ 0 & - 1 & 0 \\ 0 & 0 & 1\end{bmatrix} = \begin{bmatrix}- \frac{3}{2} & \frac{3}{2} & - \frac{3}{2} \\ 4 & - 3 & 1 \\ \frac{5}{2} & \frac{- 3}{2} & \frac{1}{2}\end{bmatrix} A \left[\text{ Applying }R_1 \to R_1 - R_3 \right]\]
\[ \Rightarrow \begin{bmatrix}1 & 0 & 0 \\ 0 & - 1 & 0 \\ 0 & 0 & 1\end{bmatrix} = \begin{bmatrix}\frac{1}{2} & \frac{- 1}{2} & \frac{1}{2} \\ 4 & - 3 & 1 \\ \frac{5}{2} & \frac{- 3}{2} & \frac{1}{2}\end{bmatrix} A \left[\text{ Applying }R_1 \to \frac{- 1}{3} R_1 \right]\]
\[ \Rightarrow \begin{bmatrix}1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1\end{bmatrix} = \begin{bmatrix}\frac{1}{2} & \frac{- 1}{2} & \frac{1}{2} \\ - 4 & 3 & - 1 \\ \frac{5}{2} & \frac{- 3}{2} & \frac{1}{2}\end{bmatrix} A \left[\text{ Applying }R_2 \to - R_2 \right]\]

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 6 | पृष्ठ ३४

संबंधित प्रश्न

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

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


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

`[(1,2,3),(0,2,4),(0,0,5)]`


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

`[(2,1,3),(4,-1,0),(-7,2,1)]`


For the matrix A = `[(3,2),(1,1)]` find the numbers a and b such that A2 + aA + bI = O.


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,-2,1),(-2,3,1),(1,1,5)]` verify that

  1. [adj A]–1 = adj (A–1)
  2. (A–1)–1 = A

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:
\[\begin{bmatrix}- 3 & 5 \\ 2 & 4\end{bmatrix}\]

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

Compute the adjoint of the following matrix:

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

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


Compute the adjoint of the following matrix:

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

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


For the matrix 

\[A = \begin{bmatrix}1 & - 1 & 1 \\ 2 & 3 & 0 \\ 18 & 2 & 10\end{bmatrix}\] , show that A (adj A) = O.

Find the inverse of the following matrix:

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

Given  \[A = \begin{bmatrix}5 & 0 & 4 \\ 2 & 3 & 2 \\ 1 & 2 & 1\end{bmatrix}, B^{- 1} = \begin{bmatrix}1 & 3 & 3 \\ 1 & 4 & 3 \\ 1 & 3 & 4\end{bmatrix}\] . Compute (AB)−1.


If  \[A = \begin{bmatrix}4 & 3 \\ 2 & 5\end{bmatrix}\], find x and y such that 

\[A^2 = xA + yI = O\] . Hence, evaluate A−1.

If \[A = \begin{bmatrix}3 & - 2 \\ 4 & - 2\end{bmatrix}\], find the value of \[\lambda\]  so that \[A^2 = \lambda A - 2I\]. Hence, find A−1.


Show that \[A = \begin{bmatrix}5 & 3 \\ - 1 & - 2\end{bmatrix}\] satisfies the equation \[x^2 - 3x - 7 = 0\]. Thus, find A−1.


Show that \[A = \begin{bmatrix}6 & 5 \\ 7 & 6\end{bmatrix}\] satisfies the equation \[x^2 - 12x + 1 = O\]. Thus, find A−1.


If \[A = \begin{bmatrix}3 & - 3 & 4 \\ 2 & - 3 & 4 \\ 0 & - 1 & 1\end{bmatrix}\] , show that \[A^{- 1} = A^3\]


Find the inverse by using elementary row transformations:

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


Find the inverse by using elementary row transformations:

\[\begin{bmatrix}3 & 10 \\ 2 & 7\end{bmatrix}\]


Find the inverse by using elementary row transformations:

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


Find the inverse by using elementary row transformations:

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


Find the inverse by using elementary row transformations:

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


If A is a square matrix, then write the matrix adj (AT) − (adj A)T.


If A is a non-singular symmetric matrix, write whether A−1 is symmetric or skew-symmetric.


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


Find the inverse of the matrix \[\begin{bmatrix} \cos \theta & \sin \theta \\ - \sin \theta & \cos \theta\end{bmatrix}\]


If A, B are two n × n non-singular matrices, then __________ .


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


If \[A = \frac{1}{3}\begin{bmatrix}1 & 1 & 2 \\ 2 & 1 & - 2 \\ x & 2 & y\end{bmatrix}\] is orthogonal, then x + y =

(a) 3
(b) 0
(c) − 3
(d) 1


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


(A3)–1 = (A–1)3, where A is a square matrix and |A| ≠ 0.


A square matrix A is invertible if det A is equal to ____________.


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


If A = `[(0, 1),(0, 0)]`, then A2023 is equal to ______.


To raise money for an orphanage, students of three schools A, B and C organised an exhibition in their residential colony, where they sold paper bags, scrap books and pastel sheets made by using recycled paper. Student of school A sold 30 paper bags, 20 scrap books and 10 pastel sheets and raised ₹ 410. Student of school B sold 20 paper bags, 10 scrap books and 20 pastel sheets and raised ₹ 290. Student of school C sold 20 paper bags, 20 scrap books and 20 pastel sheets and raised ₹ 440.

Answer the following question:

  1. Translate the problem into a system of equations.
  2. Solve the system of equation by using matrix method.
  3. Hence, find the cost of one paper bag, one scrap book and one pastel sheet.

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×