Class 12 Maths – RD Sharma Chapter 5 : Algebra of Matrices Exercise 5.3 Solutions (Step-by-Step Guide)

RD Sharma Chapter 5 : Algebra of Matrices Exercise 5.3 Solutions

  1. Compute the indicated product : [[a, b], [-b, a]] [[a, -b], [b, a]] Watch Solution
  2. Compute the indicated product : [[1, -2], [2, 3]] [[1, 2, 3], [-3, 2, -1]] Watch Solution
  3. Compute the indicated product : [[2, 3, 4], [3, 4, 5], [4, 5, 6]] [[1, -3, 5], [0, 2, 4], [3, 0, 5]] Watch Solution
  4. Show that AB ≠ BA in the following : A = [[5, -1], [6, 7]] and B = [[2, 1], [3, 4]] Watch Solution
  5. Show that AB ≠ BA in the following A= [[-1, 1, 0], [0, -1, 1], [2, 3, 4]] and B = [[1, 2, 3], [0, 1, 0], [1, 1, 0]] Watch Solution
  6. Show that AB ≠ BA in the following A = [[1, 3, 0], [1, 1, 0], [4, 1, 0]] and B = [[0, 1, 0], [1, 0, 0], [0, 5, 1]] Watch Solution
  7. Compute the products AB and BA whichever exists in the case : A = [[1, -2], [2, 3]] and B = [[1, 2, 3], [2, 3, 1]] Watch Solution
  8. Compute the products AB and BA whichever exists in the case: A = [[3, 2], [-1, 0], [-1, 1]] and B = [[4, 5, 6], [0, 1, 2]] Watch Solution
  9. Compute the products AB and BA whichever exists in the case: A = [1, -1, 2, 3] and B = [[0], [1], [3], [2]] Watch Solution
  10. Compute the products AB and BA whichever exists in the case : [a, b] [[c], [d]] + [a, b, c, d] [[a], [b], [c], [d]] Watch Solution
  11. Show that AB ≠ BA in each of the case : A=[[1, 3, -1], [2, -1, -1], [3, 0, -1]] and B=[[-2, 3, -1], [-1, 2, -1], [-6, 9, -4]] Watch Solution
  12. Evaluate the following : ([[1, 3], [-1, -4]] + [[3, -2], [-1, 1]) [[1, 3, 5], [2, 4, 6]] Watch Solution
  13. Evaluate the following : [1, 2, 3] [[1, 0, 2], [2, 0, 1], [0, 1, 2]] [[2[, [4], [6]] Watch Solution
  14. Evaluate the following : [[1, -1], [0, 2], [2, 3]] ([[1, 0, 2], [2, 0, 1]] – [[0, 1, 2], [1, 0, 2]]) Watch Solution
  15. If A = [[1, 0], [0, 1]], B = [[1, 0], [0, -1]] and C = [[0, 1], [1, 0]], then show that A^2=B^2=C^2=I2. Watch Solution
  16. If A = [[2, -1], [3, 2]] and B = [[0, 4], [-1, 7]], find 3A^2 – 2B + I. Watch Solution
  17. If A = [[4, 2], [-1, 1]], prove that (A – 2I) (A – 3I) = O. Watch Solution
  18. If A=[[1, 1], [0, 1]], show that A^2 = [[1, 2], [0, 1]] and A^3 = [[1, 3], [0, 1]] Watch Solution
  19. If A=[[ab, b^2], [-a^2, -ab]], show tht A^2 = O. Watch Solution
  20. If A=[[cos2θ, sin2θ], [-sin2θ, cos2θ]], find A^2 Watch Solution
  21. If A = [[2, -3, -5], [-1, 4, 5], [1, -3, -4]] and B = [[-1, 3, 5], [1, -3, -5], [-1, 3, 5]], show that AB = BA = O3×3 Watch Solution
  22. If A = [[0, c, -b], [-c, 0, a], [b, -a, 0] and B = [[a^2, ab, ac], [ab, b^2, bc], [ac, bc, c^2]], show that AB = BA = O3×3 Watch Solution
  23. If A = [[2, -3, -5], [-1, 4 ,5], [1, -3, -4]] and B = [[2, -2, -4], [-1, 3, 4], [1, -2, -3]], show that AB = A and BA = B. Watch Solution
  24. Let A = [[-1, 1, -1], [3, -3, 3], [5, 5, 5]] and B = [[0, 4, 3], [1, -3, -3], [-1, 4, 4]], compare A^2 – B^2 Watch Solution
  25. For the matrix verify the associativity of matrix multiplication i.e. (AB)C = A(BC). A = [[1, 2, 0], [-1, 0, 1]], B=[[1, 0], [-1, 2], [0, 3]] and C=[[1], [-1]] Watch Solution
  26. For the matrix verify the associativity of matrix multiplication i.e. (AB)C = A(BC). A = [[4, 2, 3], [1, 1, 2], [3, 0, 1]], B = [[0, -1, 1], [0, 1, 2], [2, -1, 1]] and C = [[1, 2, -1], [3, 0, 1], [0, 0, 1]] Watch Solution
  27. For the following matrices verify the distributivity of matrix multiplication over matrix addition i.e. A(B+C) = AB + AC. A = [[1, -1], [0, 2]], B = [[-1, 0], [2, 1]] and C = [[0, 1], [1, -1]] Watch Solution
  28. For the matrix verify the distributivity of matrix multiplication over matrix addition i.e. A(B + C) = AB + AC. A = [[4, 2, 3], [1, 1, 2], [3, 0, 1]], B = [[1, -1, 1], [0, 1, 2], [2, -1, 1]] and C = [[1, 2, -1], [3, 0, 1], [0, 0, 1]] Watch Solution
  29. If A = [[2, 0, -2], [3, -1, 0], [-2, 1, 1]], B = [[0, 5, -4], [-2, 1, 3], [-1, 0, 2]] and C = [[1, 5, 2], [-1, 1, 0], [0, -1, 1]], verify that A(B – C) = AB – AC. Watch Solution
  30. Compute the elements a43 and a22 of the matrix: A = [[0, 1, 0], [2, 0, 2], [0, 3, 2], [4, 0, 4]] [[2, -1], [-3, 2], [4, 3]] [[0, 1, -1, 2, -2], [3, -3, 4, -4, 0]] Watch Solution
  31. If A = [[0, 1, 0], [0 0 1], [p, q, r]] and I is the identity matrix of order 3, show that A^3 = pI + qA + rA^2 Watch Solution
  32. If ω is a complex cube root of unity, show that ([[1, ω, ω^2], [ω, ω^2, 1], [ω^2, 1, ω]] + [[ω, ω^2, 1], [ω^2, 1, ω], [ω^2, 1, ω], [ω, ω^2, 1]]) [[1], [ω], [ω^2]] = [[0], [0], [0]] Watch Solution
  33. If A=[[2, -3, -5], [-1, 4, 5], [1, -3, -4]], show that A^2 = A. Watch Solution
  34. If A = [[4, -1, -4], [3, 0, -4], [3, -1, -3]]. show that A^2 = I3 Watch Solution
  35. If [1, 1, x] [[1, 0, 2], [0, 2, 1], [2, 1, 0]] [[1], [1], [1]] = 0, find x. Watch Solution
  36. If [[2, 3], [5, 7]] [[1, -3], [-2, 4]] = [[-4, 6], [-9, x]], find x Watch Solution
  37. If [x, 4 ,1] [[2, 1, 2], [1, 0, 2], [0, 2, -4]] [[x], [4], [-1]] = 0, find x. Watch Solution
  38. If [1, -1, x][[0, 1, -1], [2, 1, 3], [1, 1, 1]] [[0], [1], [1]] = 0 find x. Watch Solution
  39. If A = [[3, -2], [4, -2]] and I = [[1, 0], [0, 1]], then prove that A^2 – A + 2I = 0. Watch Solution
  40. If A = [[3, 1], [-1, 2]], and I = [[1, 0], [0, 1]], then find λ so that A^2 = 5A + λI. Watch Solution
  41. If A = [[3, 1], [-1, 2]], show that A^2 – 5A + 7I2 = O. Watch Solution
  42. If A = [[2, 3], [-1, 0]], show that A^2 – 2A + 3I2 = O. Watch Solution
  43. Show that the matrix A = [[2, 3], [1, 2]] satisfies the equation A^3 – 4A^2 + A = O. Watch Solution
  44. Show that the matrix A = [[5, 3], [12, 7]] is a root of the equation A^2 – 12A – I = O. Watch Solution
  45. If A = [[3, -5], [-4, 2]] , find A^2 – 5A + 14I. Watch Solution
  46. If A = [[3, 1], [-1, 2]], show that A^2 – 5A + 7I = O. Use this to find A^4. Watch Solution
  47. If A = [[3, -2], [4, -2]], find k such that A^2 = kA – 2I2 Watch Solution
  48. If A = [[1, 0],[-1, 7]], find k such that A^2 – 8A + kI = O. Watch Solution
  49. If A = [[1, 2], [2, 1]] and f(x) = x^2 – 2x – 3, show that f(A) = O. Watch Solution
  50. If A = [[2, 3], [1, 2]] and I = [[1, 0], [0, 1]], then find λ, μ so that A^2 = λA + μI. Watch Solution
  51. Find the value of x for which the matrix product. [[2, 0, 7], [0, 1, 0], [1, -2, 1]] [[-x, 14, 7x], [0, 1, 0], [x, -4x, -2x]] equal to an identity matrix. Watch Solution
  52. Solve the matrix equation [x, 1], [[1, 0], [-2, -3]] [[x], [5]] = 0 Watch Solution
  53. Solve the matrix equation [1, 2, 1] [[1, 2, 0], [2, 0, 1], [1, 0, 2]] [[0], [2], [x]] = 0 Watch Solution
  54. Solve the matrix equation [x, -5, -1] [[1, 0, 2], [0, 2, 1], [2, 0, 3]] [[x], [4], [1]] = 0 Watch Solution
  55. Solve the matrix equation [2x, 3] [[1, 2], [-3, 0], [[x], [8]] = 0 Watch Solution
  56. If A = [[1, 2, 0], [3, -4, 5], [0, -1, 3]], compare A^2 – 4A + 3I3 Watch Solution
  57. If f(x) = x^2 – 2x, find f(A), where A = [[0, 1, 2], [4, 5 ,0], [0, 2, 3]] Watch Solution
  58. If f(x) = x^3 + 4x^2 – x, find f(A), where A = [[0, 1, 2], [2, -3, 0], [1, -1, 0]] Watch Solution
  59. If A = [[1, 0, 2], [0, 2, 1], [2, 0, 3]], then show that A is a root of the polynomial f(x) = x^3 – 6x^2 + 7x + 2. Watch Solution
  60. If A = [[1, 2, 2], [2, 1, 2], [2, 2, 1]], then prove that A^2 – 4A + 5I = O. Watch Solution
  61. If A = [[3, 2, 0], [1, 4, 0], [0, 0, 5]], show that A^2 – 7A + 10I3 = O. Watch Solution
  62. Without using the concept of inverse of matrix, find the matrix [[x, y], [z, u]] such that [[5, -7], [-2, 3]] [[x, y], [z, u]] = [[-16, -6], [7, 2]] Watch Solution
  63. Find the matrix A such that [[1, 1], [0, 1]] A = [[3, 3, 5], [1, 0, 1]] Watch Solution
  64. Find the matrix A such that A[[1, 2, 3], [4, 5, 6]] = [[-7, -8, -9], [2, 4, 6]] Watch Solution
  65. Find the matrix A such that [[4], [1], [3]]A = [[-4, 8, 4], [-1, 2, 1], [-3, 6, 3]] Watch Solution
  66. Find the matrix such that [2, 1, 3] [[-1, 0, -1], [-1, 1, 0], [0, 1, 1]] [[1], [0], [-1]] = A Watch Solution
  67. Find the matrix A such that [[2, -1], [1, 0], [-3, 4]] A = [[-1, -8, -10], [1, -2, -5], [9, 22, 15]] Watch Solution
  68. Find the matrix A such that A [[1, 2, 3], [4, 5, 6]] = [[-7, -8, -9], [2, 4, 6], [11, 10, 9]] Watch Solution
  69. Find a 2×2 matrix A such that A[[1, -2], [1, 4]] = 6I2 Watch Solution
  70. If A = [[0, 0], [4, 0]], find A^16 Watch Solution
  71. If A=[[0, -x], [x, 0]], B = [[0, 1], [1, 0]] and x^2 = -1, then show that (A + B)^2 = A^2 + B^2 Watch Solution
  72. If A=[[1, 0, -3], [2, 1, 3], [0, 1, 1]], then verify that A^2 + A = A(A + I), where I is the identity matrix. Watch Solution
  73. If A=[[3, -5], [-4, 2]], then find A^2 – 5A – 14I. Hence, obtain A^2 – 5A + 14I. Hence, obtain A^3 Watch Solution
  74. If P(x) = [[cos x, sin x], [-sin x, cos x]], then show that P(x) P(y) = P(x + y) = P(y)P(x). Watch Solution
  75. If P = [[x, 0, 0], [0, y, 0], [0, 0, z]] and Q = [[a, 0, 0], [0, b, 0], [0, 0, c]], prove that PQ = [[xa, 0, 0], [0, yb, 0], [0, 0, zc]] = QP Watch Solution
  76. If A = [[2, 0, 1], [2, 1, 3], [1, -1, 0]], find A^2 – 5A + 4I and hence find a matrix X such that A^2 – 5A + 4I + X = 0. Watch Solution
  77. If A = [[1, 1], [0, 1]], prove that A^n = [[1, n], [0, 1]] for all positive integers n. Watch Solution
  78. If A = [[a, b], [0, 1]], prove that A^n = [[a^n, b((a^n-1)/(a-1))], [0, 1]] for every positive integer n. Watch Solution
  79. If A=[[cos θ, isin θ], [isin θ, cos θ]], then prove by principle of mathematical induction that A^n =[[cos nθ, isin nθ], [isin nθ, cos nθ]] for all n ∈ N. Watch Solution
  80. If A = [[cos α + sin α, √2sin α],[-√2sin α, cos α – sin α]], prove that If A^n = [[cos nα + sin nα, √2sin nα],[-√2sin nα, cos nα – sin nα]] for all n ∈ N Watch Solution
  81. If A=[[1, 1, 1], [0, 1, 1], [0, 0, 1]], then use the principle of mathematical induction to show that A^n = [[cos α + sin α, √2sin α], [-√sinn α, cos nα – sin nα]] for all n ∈ N. Watch Solution
  82. If B,C are n rowed square matrices and if A = B + C, BC = CB, C^2 = O. then show that for every n ∈ N, A^n+1 = B^n (B + (n + 1)C). Watch Solution
  83. If A = diag(a, b, c), show that A^n = diag(a^n, b^n, c^n) for all positive integer n. Watch Solution
  84. If A is a square matrix, using mathematical induction prove that (A^T)^n=(A^n)^T for all n ∈ N. Watch Solution
  85. A matrix X has a+b rows and a+2 column while the matrix Y has b+1 rows and a+3 columns. Both matrices XY and YX exist. Find a and b. Can you say XY and YX are of the same type? Are they equal. Watch Solution
  86. Give example of matrix : A and B such that AB ≠ BA. Watch Solution
  87. Give example of matrix : A and B such that AB = O but A ≠ O, B ≠ O. Watch Solution
  88. Give example of matrix : A and B such that AB = O but BA ≠ O. Watch Solution
  89. Give example of matrix : A, B and C such that AB = AC but B ≠ C, A ≠ O. Watch Solution
  90. Let A and B be square matrix of the same order. Does (A + B)^2 = A^2 + 2AB + B^2 hold ? If not, why? Watch Solution
  91. If A and B are square matrices of the same order, explain, why in general (A + B)^2 ≠ A^2 + 2AB + B^2 Watch Solution
  92. If A and B are square matrices of the same order, explain, why in general (A – B)^2 ≠ A^2 – 2AB + B^2 Watch Solution
  93. If A and B are square matrices of the same order, explain, why in general (A + B)(A – B) ≠ A^2 – B^2 Watch Solution
  94. Let A and B be square matrices of the other 3×3. Is (AB)^2 = A^2 B^2 ? Give reasons. Watch Solution
  95. If A and B are square matrices of the same order such that AB = BA, then show that (A + B)^2 = A^2 + 2AB + B^2 Watch Solution
  96. Let A = [[1, 1, 1], [3, 3, 3]], B = [[3, 1], [5, 2], [-2, 4]] and C = [[4, 2], [-3, 5], [5, 0]] Verify that AB = AC though B ≠ C, A ≠ O. Watch Solution
  97. Three shopkeepers A, B and C go to a store by stationary. A purchases 12 dozen notebooks, 5 dozen pens and 6 dozen pencils. B purchases 10 dozen notebooks, 6 dozen pens and 7 dozen pencils. C purchases 11 dozen notebooks, 13 dozen pend and 8 dozen pencils. A notebook costs 40 paise, a pen costs ₹1.25 and a pencil costs 35 paise. Use matrix multiplication to calculate each individual’s bill. Watch Solution
  98. The cooperative stores of a particular school has 10 dozen physics books, 8 dozen chemistry books and 5 dozen mathematics books. Their selling prices are ₹8.30, ₹3.45 and ₹4.50 each respectively. Find the total amount the store will receive from selling all the items. Watch Solution
  99. In a legislative assembly election, a political group hired a public relations firm to promote its candidates in three ways: telephone, house calls and letters. The cost per contact (in paise) is given matrix A as A=Cost per contact [[40] – Telephone, [100]-House call, [50]-Letter] The number of contacts of each type made in two cities X and Y is given in matrix B as Find the total amount spend by the group in the two cities X and Y. Watch Solution
  100. A trust fund has ₹30000 that must be invested in two different types of bonds. The first bond pays 5% interest per year, and the second bond pays 7% interest per year. Using the trust fund must obtain an annual total interest of (i) ₹1800 (ii) ₹2000. Watch Solution
  101. To promote making of toilets for women, an organisation tried to generate awareness through (i) house calls (ii) letters, and (iii) announcements. The cost for each mode per attempt is given below: (i) ₹50 (ii) ₹20 (iii) ₹40 The number of attempts made in three village X, Y and Z are given below: Find the total cost incurred by the organisation for three villages separately, using matrices. Watch Solution
  102. There are 2 families A and B. There are 4 men, 6 women and 2 children in family A, and 2 men, 2 women and 4 children in family B. The recommend daily amount of calories is 2400 for men, 1900 for women, 1800 for children and 45 grants of proteins for men, 55 grams for women and 33 grams for children. Represent the above information using matrix. Using matrix multiplication, calculate the total requirement of calories and proteins for each of the two families. What awareness can you create among people about the planned diet from this question ? Watch Solution
  103. In a parliament election, a political party hired a public relations firm to promote its candidates in three ways – telephone, house calls and letters. The cost per contact (in paisa) is given in matrix A as The number of contacts of each type made in two cities X and Y is given in the matrix B as Find the total amount spent by the party in the two cities. What should one consider before casting his/her vote – party’s promotional activity or their social activities? Watch Solution
  104. The monthly incomes of Aryan and Babbar are in the ratio 3:4 and their monthly expenditures are in the ratio 5:7. If each saves ₹15000 per month, find their monthly incomes using matrix method. This problem reflects which value? Watch Solution
  105. A trust invested some money in two type of bonds. The first boys pays 10% interest and second bond pays 12% interest. The trust received ₹2800 as interest. However, if trust had interchanged money in bonds, they would have got ₹100 less as interest. Using matrix method, find the amount invested by the trust. Watch Solution

 

 

ALGEBRA OF MATRICES R.D. Sharma Class 12th Math

  1. Algebra of Matrices Exercise 5.1 Video Solution
  2. Algebra of Matrices Exercise 5.2 Video Solution
  3. Algebra of Matrices Exercise 5.3 Video Solution
  4. Algebra of Matrices Exercise 5.4 Video Solution
  5. Algebra of Matrices Exercise 5.5 Video Solution
  6. Algebra of Matrices Very Short Answer Questions (VSAQs) Video Solution
  7. Algebra of Matrices Multiple Choice Questions (MCQs) Video Solution

 

 

 

Spread the love

Leave a Comment

Your email address will not be published. Required fields are marked *