03 Matrices
Exercise 01
Question:
Construct a 2×2 matrix, A=, whose elements are given by: (i) =/2 (ii) =i/j (iii) =/2
Answer:
Answer:
(i) A =
(ii) A =
(iii) A =
Question:
In the matrix, write : A=(i) The order of the matrix (ii) The number of elements (iii) Write the elements a13,a21,a33,a24,a23
Answer:
(i) The order of the matrix is 3x4
(ii) The number of elements is 12
(iii) a13 = √3, a21 = 35, a33 = 17, a24 = 12, a23 = 5/2
Question:
If a matrix has 18 elements , what are the possible orders it can have? what, if it has 5 elements?
Answer:
If a matrix has 18 elements, the possible orders it can have are 2x9, 3x6, 6x3, 9x2.
If a matrix has 5 elements, the possible orders it can have are 1x5, 5x1.
Question:
Which of the given values of x and y make the following pair of matrices equal.= A x=−1/3,y=7 B Not possible to find C y=7,x=−2/3 D x=−1/3,y=−2/3
Answer:
The answer is C. y=7, x=-2/3
Question:
The number of all possible matrices of order 3×3 with each entry 0 or 1 is: A 27 B 18 C 81 D 512
Answer:
Answer: C 81
Question:
Find the value of x,y and z from the following equation: (i) = (ii) = (iii) =
Answer:
Solution:
(i) 4x + 3y = 5z
Substituting the given values, we get
4(4) + 3y = 5z
16 + 3y = 5z
3y = 5z - 16
y = (5z - 16)/3
(ii) x + y + 2 = 6
Substituting the value of y from step (i), we get
x + (5z - 16)/3 + 2 = 6
x + 5z - 16 + 6 = 18
x + 5z = 34
(iii) x + y + z = 9
Substituting the value of y from step (i), we get
x + (5z - 16)/3 + z = 9
x + 5z - 16 + 3z = 27
4z = 27 - x - 16
z = (27 - x - 16)/4
Substituting the value of z in equation (ii), we get
x + 5(27 - x - 16)/4 = 34
4x + 135 - 5x - 80 = 136
x = 25
Substituting the value of x in equation (i) and (iii), we get
y = (5(27) - 16)/3 = 33
z = (27 - 25 - 16)/4 = 3
Hence, x = 25, y = 33 and z = 3
Question:
If a matrix has 24 elements, what are the possible order it can have? What, if it has 13 elements?
Answer:
If a matrix has 24 elements, it can have an order of 2 x 12, 3 x 8, 4 x 6, 6 x 4, 8 x 3, or 12 x 2.
If a matrix has 13 elements, it can have an order of 1 x 13, 2 x 6.5, 3 x 4.5, 4 x 3.25, 5 x 2.6, 6 x 2.16, or 13 x 1.
Question:
Find the value of a,b,c and d from the equation: <math xmlns = “http://www.w3.org/1998/Math/MathML"
Answer:
Step 1: Rewrite the equation as a system of linear equations.
a - b = -1 2a + c = 5 2a - b = 0 3c + d = 13
Step 2: Solve for a in the first and third equations by adding them together.
a - b + 2a - b = -1 + 0 3a = -1 a = -1/3
Step 3: Substitute the value of a in the second equation and solve for c.
2(-1/3) + c = 5 -2/3 + c = 5 c = 5 + 2/3
Step 4: Substitute the values of a and c in the fourth equation and solve for d.
3(5 + 2/3) + d = 13 15 + 2 + d = 13 d = 1
Question:
Construct a 3×4 matrix, whose elements are given by (i) =1/2∣−3i+j∣ (ii) =2i−j
Answer:
Solution:
(i) A = [1/2|-3i+j|, 1/2|-3i+j|, 1/2|-3i+j|] [1/2|-3i+j|, 1/2|-3i+j|, 1/2|-3i+j|] [1/2|-3i+j|, 1/2|-3i+j|, 1/2|-3i+j|]
(ii) A = [2i-j, 2i-j, 2i-j] [2i-j, 2i-j, 2i-j] [2i-j, 2i-j, 2i-j]
JEE NCERT Solutions (Mathematics)
01 Relations and Functions
02 Inverse Trigonometric Functions
03 Matrices
04 Determinants
05 Continuity and Differentiability
- Exercise 01
- Exercise 02
- Exercise 03
- Exercise 04
- Exercise 05
- Exercise 06
- Exercise 07
- Exercise 08
- Miscellaneous Exercises
06 Application of Derivatives
07 Integrals
08 Application of Integrals
09 Vectors
10 Three Dimensional Geometry
11 Linear Programming
12 Probability