English

If A = [2-35-4-61],B=[-122203]andC=[4 3-14-21] Show that A + B = B + A - Mathematics and Statistics

Advertisements
Advertisements

Question

If A = `[(2, -3),(5, -4),(-6, 1)], "B" = [(-1, 2),(2, 2), (0, 3)] and "C" = [(4,  3),(-1, 4),(-2, 1)]` Show that A + B = B + A

Sum

Solution

A + B = `[(2, -3),(5, -4),(-6, 1)] + [(-1, 2),(2, 2), (0, 3)]`

= `[(2 - 1, -3 + 2),(5 + 2, -4 + 2),(-6 + 0, 1 + 3)]`

∴ A + B = `[(1, -1),(7, -2),(-6, 4)]`  ....(i)

B + A = `[(-1, 2),(2, 2), (0, 3)] + [(2, -3),(5, -4),(-6, 1)]`

= `[(-1 + 2, 2 - 3),(2 + 5, 2 - 4),(0 - 6, 3 + 1)]`

∴ B + A = `[(1, -1),(7, -2),(-6, 4)]`   ....(ii)

From (i) and (ii), we get

A + B = B + A

shaalaa.com
  Is there an error in this question or solution?
Chapter 4: Determinants and Matrices - Exercise 4.5 [Page 86]

APPEARS IN

RELATED QUESTIONS

Find the values of x and y if

`2 [(x,5),(7,y-3)] [(3,-4),(1,2)] = [(7,6),(15,14)]`


Solve the following equations by reduction method: 

x + y + z = 6,

3x - y + 3z = 10

5x + y - 4z = 3 


Solve the following equations by reduction method: 

x+ y+z = 6,

3x-y+3z = 10

5x+ y-4z = 3 


Find x , y , z , w if `[("x+y","x-y"),("y+z+w","2w-z")]` = `[(2,-1),(9,5)]`


Simplify the following :

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


If A = `[(1,2,3),(2,"a",2),(5,7,3)]` is a singular matrix , find the value of 'a'.


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

verify that A (adj A) = (adj A) A = |A| . I


If A = `[(5, 1, -4),(3, 2, 0)]`, find (AT)T.


If A = `[(7, 3, 1),(-2, -4, 1),(5, 9, 1)]`, find (AT)T.


Find a, b, c, if `[(1, 3/5, "a"),("b", -5, -7),(-4, "c", 0)]` is a symmetric matrix.


For each of the following matrices, find its transpose and state whether it is symmetric, skew- symmetric or neither.

`[(1, 2, -5),(2, -3, 4),(-5, 4, 9)]`


For each of the following matrices, find its transpose and state whether it is symmetric, skew-symmetric, or neither.

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


For each of the following matrices, find its transpose and state whether it is symmetric, skew- symmetric or neither.

`[(0, 1 + 2"i", "i" - 2),(-1 - 2"i", 0, -7),(2 - "i", 7, 0)]`


Solve the following equations for X and Y, if 3X − Y = `[(1, -1),(-1, 1)]`  and X – 3Y = `[(0, -1),(0, -1)]`.


Find matrices A and B, if 2A – B = `[(6, -6, 0),(-4, 2, 1)]` and A – 2B = `[(3, 2, 8),(-2, 1, -7)]`.


Find AT,  if A = `[(1, 3),(-4, 5)]`


Find AT, if A = `[(2, -6, 1),(-4, 0, 5)]`


If [aij]3×3, where aij = 2(i – j), find A and AT. State whether A and AT both are symmetric or skew-symmetric matrices?


If A = `[(5, -3),(4, -3),(-2, 1)]`, prove that (AT)T = A.


If A = `[(1, 2, -5),(2, -3, 4),(-5, 4, 9)]`, prove that AT = A.


If A = `[(5, 4),(-2, 3)]` and B = `[(-1, 3),(4, -1)]`, then find CT, such that 3A – 2B + C = I, whre I is e unit matrix of order 2.


If A = `[(7, 3, 0),(0, 4, -2)], "B" = [(0, -2, 3),(2, 1, -4)]`, then find 5AT – 5BT.


If A = `[(1, 0, 1),(3, 1, 2)], "B" = [(2, 1, -4),(3, 5, -2)] "and"  "C" = [(0, 2, 3),(-1, -1, 0)]`, verify that (A + 2B + 3C)T = AT + 2BT + CT.


Express each of the following matrix as the sum of a symmetric and a skew symmetric matrix `[(3, 3, -1),(-2, -2, 1),(-4, -5, 2)]`.


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


Fill in the blank:

A = `[(3),(1)]` is ........................ matrix.


State whether the following is True or False :

Every scalar matrix is unit matrix.


State whether the following is True or False :

If A and B are square matrices of same order, then (A + B)2 = A2 + 2AB + B2.


If A = `[(1, -2),(5, 3)], "B" = [(1, -3),(4, -7)]`, then find the matrix A – 2B + 6I, where I is the unit matrix of order 2.


Find x and y, if `[(2x + y, -1, 1),(3, 4y, 4)] + [(-1, 6, 4),(3, 0, 3)] = [(3, 5, 5),(6, 18, 7)]`


If = `[(2"a" + "b", 3"a" - "b"),("c" + 2"d", 2"c" - "d")] = [(2, 3),(4, -1)]`, find a, b, c and d.


There are two book shops owned by Suresh and Ganesh. Their sales (in Rupees) for books in three subject – Physics, Chemistry and Mathematics for two months, July and August 2017 are given by two matrices A and B.

July sales (in Rupees), Physics Chemistry Mathematics.

A = `[(5600, 6750, 8500),(6650, 7055, 8905)]"First Row Suresh"/"Second Row Ganesh"`

August sales(in Rupees), Physics Chemistry Mathematics

B = `[(6650, 7055, 8905),(7000, 7500, 10200)]"First Row Suresh"/"Second Row Ganesh"` then,

Find the increase in sales in Rupees from July to August 2017.


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


Choose the correct alternative:

If A = `[(1, 3/5, x),(y, -5, -7),(-4, -7, 0)]` is a symmetric matrix, then the values of x and y are ______ respectively.


Choose the correct alternative:

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


Choose the correct alternative:

If A and B are two square matrices of order 3, then (AB)T = ______


In a Skew symmetric matrix, all diagonal elements are ______


Find k, if A = `[(3, -2),(4, -2)]` and A2 = kA – 2I, where I is identity matrix of order 2


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×