हिंदी

Find the inverse of the following matrix by the adjoint method. [10033052-1] - Mathematics and Statistics

Advertisements
Advertisements

प्रश्न

Find the inverse of the following matrix by the adjoint method.

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

योग

उत्तर

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

∴ |A| = `|(1, 0, 0),(3, 3, 0),(5, 2, -1)|`

= 1(−3 − 0) − 0 + 0

= −3 ≠ 0

∴ A−1 exist

First we have to find the co-factor matrix

= [Aij]3×3′ where Aij = (− 1)i+jMij

Now, A11 = (−1)1+1M11 = 1`|(3, 0),(2, -1)|` = 1(−3 − 0) = −3

A12 = (−1)1+2M12 = − 1`|(3, 0),(5, -1)|` = −1(−3 − 0) = 3

A13 = (−1)1+3M13 = 1`|(3, 3),(5, 2)|` = 1(6 − 15) = −9

A21 = (−1)2+1M21 = −1`|(0, 0),(2, -1)|` = −1(0 − 0) = 0

A22 = (−1)2+2M22 = 1`|(1, 0),(5, -1)|` = 1(−1 − 0) = −1

A23 = (−1)2+3M23 = −1`|(1, 0),(5, 2)|` = −1(2 − 0) = −2

A31 =(−1)3+1M31 = 1`|(0, 0),(3, 0)|` = 1(0 − 0) = 0

A32 = (−1)3+2M32 = −1`|(1, 0),(3, 0)|` = −1(0 − 0) = 0

A33 = (−1)3+3M33 = 1`|(1, 0),(3, 3)|` = 1(3 − 0) = 3

∴ The co-factor matrix

= `[(A_11, A_12, A_13),(A_21, A_22, A_23),(A_31, A_32, A_33)]` = `[(-3, 3, -9),(0, -1, -2),(0, 0, 3)]`

∴ adj A = `[(-3, 0, 0),(3, -1, 0),(-9, -2, 3)]`

∴ A−1 = `1/|A|` (adj A)

= `-1/3[(-3, 0, 0),(3, -1, 0),(-9, -2, 3)]`

∴ A−1 = `1/3[(3, 0, 0),(-3, 1, 0),(9, 2, -3)]`

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 2: Matrics - Exercise 2.2 [पृष्ठ ५२]

संबंधित प्रश्न

 Find the inverse of the following matrix by elementary row transformations if it exists. `A=[[1,2,-2],[0,-2,1],[-1,3,0]]`


If A = `[(1, 3), (3, 1)]`, Show that A2 - 2A is a scalar matrix.


Find the co-factor of the element of the following matrix:

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


Find the matrix of the co-factor for the following matrix.

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


Find the inverse of the following matrix by the adjoint method.

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


Find the inverse of the following matrix.

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


Find the inverse of the following matrix (if they exist):

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


Find the inverse of `[(1,2,3),(1,1,5),(2,4,7)]` by the adjoint method.


Choose the correct answer from the given alternatives in the following question:

If A = `[("cos"alpha,-"sin"alpha),("sin"alpha,"cos"alpha)]`, then A-1 = _____


Choose the correct answer from the given alternatives in the following question:

For a 2 × 2 matrix A, if A(adj A) = `[(10,0),(0,10)]`, then determinant A equals


Choose the correct answer from the given alternatives in the following question:

If A−1 = `- 1/2[(1,-4),(-1,2)]`, then A = ______.


Find the inverse of the following matrices by the adjoint method `[(1, 2, 3),(0, 2, 4),(0, 0, 5)]`.


Find matrix X, if AX = B, where A = `[(1, 2, 3),(-1, 1, 2),(1, 2, 4)] "and B" = [(1),(2),(3)]`.


Choose the correct alternative.

If A is a 2 x 2 matrix such that A(adj. A) = `[(5, 0),(0, 5)]`, then |A| = _______


State whether the following is True or False :

Singleton matrix is only row matrix.


Check whether the following matrices are invertible or not:

`[(1, 0),(0, 1)]`


Check whether the following matrices are invertible or not:

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


Check whether the following matrices are invertible or not:

`[(1, 2, 3),(2, 4, 5),(2, 4, 6)]`


If ω is a complex cube root of unity, then the matrix A = `[(1, ω^2, ω),(ω^2, ω, 1),(ω, 1, ω^2)]` is


If A = `[(4, 5),(2, 5)]`, then |(2A)−1| = ______


If `[(x - y - z),(-y + z),(z)] = [(0),(5),(3)]`, then the value of x, y and z are respectively ______


If A = `[(2, 2),(-3, 2)]` and B = `[(0, -1),(1, 0)]`, then find the matrix (B−1 A−1)−1.


If A = `[(3, 1),(5, 2)]`, and AB = BA = I, then find the matrix B


If A(α) = `[(cos alpha, sin alpha),(-sin alpha, cos alpha)]` then prove that A2(α) = A(2α)


If A = `[(0, 4, 3),(1, -3, -3),(-1, 4, 4)]`, then find A2 and hence find A−1 


Choose the correct alternative:

If A is a non singular matrix of order 3, then |adj (A)| =  ______


Complete the following activity to find inverse of matrix using elementary column transformations and hence verify.

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

C1 → C1 + C3

`[("( )", 0, -1),("( )", 1, 0),("( )", 1, 3)]` B−1 = `[("( )", 0, 0),("( )", 1, 0),("( )", 0, 1)]`

C3 → C3 + C1 

`[(1, 0, 0),("( )", 1, "( )"),(3, 1, "( )")]` B−1 = `[(1, 0, "( )"),(0, 1, 0),("( )", 0, "( )")]`

C1 → C1 – 5C2, C3 → C3 – 5C2

`[(1, "( )", 0),(0, 1, 0),("( )", 1, "( )")]` B−1 = `[(1, 0, "( )"),("( )", 1, -5),(1, "( )", 2)]`

C1 → C1 – 2C3, C2 → C2 – C

`[(1, 0, 0),(0, 1, 0),(0, 0, 1)]` B−1 = `[(3, -1, "( )"),("( )", 6, -5),(5, "( )", "( )")]`

B−1 =  `[("( )", "( )", "( )"),("( )", "( )", "( )"),("( )", "( )", "( )")]`

`[(2, "( )", -1),("( )", 1, 0),(0, 1, "( )")] [(3, "( )", "( )"),("( )", 6, "( )"),("( )", -2, "( )")] = [(1, 0, 0),(0, 1, 0),(0, 0, 1)]`


Find the inverse of the following matrix:

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


Find the inverse of the following matrix:

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


If A-1 = `[(1,0,3),(2,1,-1),(1,-1,1)]`  then, find A.


Show that the matrices A = `[(2,2,1),(1,3,1),(1,2,2)]` and B = `[(4/5,(-2)/5,(-1)/5),((-1)/5,3/5,(-1)/5),((-1)/5,(-2)/5,4/5)]` are inverses of each other.


Find m if the matrix `[(1,1,3),(2,λ,4),(9,7,11)]` has no inverse.


The inverse matrix of `((3,1),(5,2))` is


The cost of 2 Kg of Wheat and 1 Kg of Sugar is ₹ 70. The cost of 1 Kg of Wheat and 1 Kg of Rice is ₹ 70. The cost of 3 Kg of Wheat, 2 Kg of Sugar and 1 Kg of rice is ₹ 170. Find the cost of per kg each item using the matrix inversion method.


If A = `[(1,2),(3,-5)]`, then A-1 = ?


If [abc] ≠ 0, then `(["a" + "b b" + "c c" + "a"])/(["b c a"])` = ____________.


If A = `[(x,1),(1,0)]` and A = A , then x = ______.


If A and Bare square matrices of order 3 such that |A| = 2, |B| = 4, then |A(adj B)| = ______.


If A2 - A + I = 0, then A-1 = ______.


If A = `[(5, -4), (7, -5)]`, then 3A-1 =  ______ 


If A–1  = `[(3, -1, 1),(-15, 6, -5),(5, -2, 2)]`, then adj A = ______.


If A = `[(2,  -3, 3),(2, 2, 3),(3, "p", 2)]` and A–1 = `[(-2/5, 0, 3/5),(-1/5, 1/5, "q"),(2/5, 1/5, -2/5)]`, then ______.


Choose the correct option:

If X, Y, Z are non zero real numbers, then the inverse of matrix A = `[(x, 0, 0),(0, y, 0),(0, 0, z)]`


If matrix P = `[(0, -tan (θ//2)),(tanθ//2, 0)]`, then find (I – P) `[(cosθ, -sinθ),(sinθ, cosθ)]`


If matrix A = `[(3, -2, 4),(1, 2, -1),(0, 1, 1)]` and A–1 = `1/k` (adj A), then k is ______.


If A = `[(cos α, sin α),(-sin α, cos α)]`, then find α satisfying `0 < α < π/2`, when A + AT = `sqrt(2)  l_2` where AT is transpose of A.


if `A = [(2,-1,1),(-1,2,-1),(1,-1,2)]` then find A−1 by the adjoint method.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×