हिंदी

If A = [122212221], show that A2 – 4A is a scalar matrix. - Mathematics and Statistics

Advertisements
Advertisements

प्रश्न

If A = `[(1, 2, 2),(2, 1, 2),(2, 2, 1)]`, show that A2 – 4A is a scalar matrix.

योग

उत्तर

A2 – 4A = A.A – 4A
= `[(1, 2, 2),(2, 1, 2),(2, 2, 1)][(1, 2, 2),(2, 1, 2),(2, 2, 1)] - 4[(1, 2, 2),(2, 1, 2),(2, 2, 1)]`

= `[(1 + 4 + 4, 2 + 2 + 4, 2 + 4 + 2),(2 + 2 + 4, 4 + 1 + 4, 4+ 2 + 2),(2 + 4 + 2, 4 + 2 + 2, 4 + 4 + 1)] - [(4, 8, 8),(8, 4, 8),(8, 8, 4)]`

= `[(9, 8, 8),(8, 9, 8),(8, 8, 9)] - [(4, 8, 8),(8, 4, 8),(8, 8, 4)]`

= `[(9 - 4, 8 - 8, 8 - 8),(8 - 8, 9 - 4, 8 - 8),(8 - 8, 8 - 8, 9 - 4)]`

= `[(5, 0, 0),(0, 5, 0),(0, 0, 5)]`, which is a scalar martix.

shaalaa.com
Properties of Matrices
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 2: Matrices - Exercise 2.3 [पृष्ठ ५६]

APPEARS IN

संबंधित प्रश्न

Evaluate : `[(3),(2),(1)][2  -4   3]`


Evaluate : `[2 - 1   3][(4),(3),(1)]`


Verify A(BC) = (AB)C, if A = `[(1, 0, 1),(2, 3, 0),(0, 4, 5)], "B" = [(2, -2),(-1, 1),(0, 3)] and "C" = [(3,2,-1), (2,0,-2)]`


Verify that A(B + C) = AB + AC, if A = `[(4, -2),(2, 3)], "B" = [(-1, 1),(3, -2)] " and C" = [(4 ,1),(2, -1)]`.


If A = `[(1, 0),(-1, 7)]`, find k, so that A2 – 8A – kI = O, where I is a 2 × 2 unit and O is null matrix of order 2.


Find k, if A = `[(3, -2),(4, -2)]` and A2 = kA – 2I.


Find x, y, x, if `{3[(2, 0),(0, 2),(2, 2)] -4[(1, 1),(-1, 2),(3, 1)]} [(1),(2)] = [(x - 3),(y - 1),(2z)]`.


Choose the correct alternative.

If A and B are square matrices of order n × n such that A2 – B2 = (A – B)(A + B), then which of the following will be always true?


Solve the following :

If A = `[(2, 5),(3, 7)], "B" = 4[(1, 7),(-3, 0)]`, find matrix A – 4B + 7I, where I is the unit matrix of order 2.


Solve the following :

If A = `[(2, -3),(3, -2),(-1, 4)],"B" = [(-3, 4, 1),(2, -1, -3)]`, verify (A + 2BT)T = AT + 2B.


Solve the following :

If A = `[(1, 2, 3),(2, 4, 6),(1, 2, 3)],"B" = [(1, -1, 1),(-3, 2, -1),(-2, 1, 0)]`, then show that AB and BA are bothh singular martices.


Solve the following :

If A = `[(2, -1),(-1, 2)]`, then show that A2 – 4A + 3I = 0.


Solve the following :

if A = `[(1, 2),(-1, 3)]`, then find A3.


Solve the following :

If A = `[(2, -4),(3, -2),(0, 1)], "B" = [(1, -1, 2),(-2, 1, 0)]`, then show that (AB)T = BTAT.


If A = `[(4, 3, 2),(-1, 2, 0)]`, B = `[(1, 2),(-1, 0),(1, -2)]`, then |AB| = ______


If matrix form of given equations 3x – y = 1 and y + 4x = 6 is AX = B, then A = ______


If A = `[(3, 1),(1, 5)]` and B = `[(1, 2),(5, -2)]`, then verify |AB| = |A||B|


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×