Determinants Complete Practice Set (150 Questions with answer keys) for CBSE, NCERT & other board exams.


Determinants are one of the most important and widely used topics in mathematics. They play a crucial role not only in school-level mathematics but also in engineering mathematics and higher mathematics, especially in areas such as linear algebra, coordinate geometry, calculus, vector spaces, and systems of linear equations. Determinants are extensively applied in solving real-world problems, finding areas of geometric figures, checking collinearity of points, and understanding advanced concepts used in engineering and scientific computations. In this post, we provide a carefully designed set of 150 practice questions on determinants, ranging from basic to advanced levels. These questions are highly useful for board classes (CBSE, NCERT, state boards) as well as for competitive examinations, helping students build strong conceptual clarity, speed, and confidence in this essential topic.

What is a Determinant?

A determinant is a single numerical value associated with a square matrix. It is widely used in algebra and coordinate geometry to:

  • solve linear equations,
  • find the area of a triangle,
  • check whether points are collinear,
  • determine invertibility of a matrix.
  • and many other fields of mathematics

A determinant is written using vertical bars.

\[ \begin{vmatrix} a & b\\ c & d \end{vmatrix} \]

Determinant of a 2 × 2 Matrix

For a 2 × 2 matrix

\[ \begin{vmatrix} a & b\\ c & d \end{vmatrix} = ad - bc \]
Example:
Evaluate \[ \begin{vmatrix} 3 & 5\\ 2 & 4 \end{vmatrix} \]

Solution:
\[ = (3 \times 4) - (5 \times 2) \] \[ = 12 - 10 = 2 \]

Determinant of a 3 × 3 Matrix

For a 3 × 3 matrix

\[ \begin{vmatrix} a & b & c\\ d & e & f\\ g & h & i \end{vmatrix} \]

Expand along the first row:

\[ = a \begin{vmatrix} e & f\\ h & i \end{vmatrix} - b \begin{vmatrix} d & f\\ g & i \end{vmatrix} + c \begin{vmatrix} d & e\\ g & h \end{vmatrix} \]
Example:
Evaluate \[ \begin{vmatrix} 1 & 2 & 3\\ 4 & 5 & 6\\ 7 & 8 & 9 \end{vmatrix} \]

Solution:
\[ =1(45-48)-2(36-42)+3(32-35) \] \[ =-3+12-9=0 \]

Shortcut for Diagonal Matrix

If a matrix is diagonal, its determinant is the product of diagonal elements.

\[ \begin{vmatrix} a & 0 & 0\\ 0 & b & 0\\ 0 & 0 & c \end{vmatrix} = abc \]
Example:
\[ \begin{vmatrix} 2 & 0 & 0\\ 0 & 3 & 0\\ 0 & 0 & 5 \end{vmatrix} = 2 \times 3 \times 5 = 30 \]

Condition for Collinearity of Points

Three points \((x_1,y_1)\), \((x_2,y_2)\), \((x_3,y_3)\) are collinear if

\[ \begin{vmatrix} x_1 & y_1 & 1\\ x_2 & y_2 & 1\\ x_3 & y_3 & 1 \end{vmatrix} = 0 \]
Example:
Check collinearity of \((1,2),(2,4),(3,6)\).

\[ \begin{vmatrix} 1 & 2 & 1\\ 2 & 4 & 1\\ 3 & 6 & 1 \end{vmatrix} = -2+2=0 \]
Hence, the points are collinear.

Area of a Triangle Using Determinants

Area of triangle with vertices \((x_1,y_1)\), \((x_2,y_2)\), \((x_3,y_3)\):

\[ \text{Area}= \frac12 \left| \begin{vmatrix} x_1 & y_1 & 1\\ x_2 & y_2 & 1\\ x_3 & y_3 & 1 \end{vmatrix} \right| \]
Example:
Find area of triangle with vertices \((1,2),(3,6),(5,2)\).

\[ \text{Area}=\frac12| -16 |=8 \]

Important Exam Shortcuts

  • If two rows or columns are identical → determinant = 0
  • If one row is a multiple of another → determinant = 0
  • Diagonal matrix → multiply diagonal elements
  • Collinear points → determinant = 0
  • Triangle area → half of absolute determinant
Check out 150 practice qustions with their answer keys.
Disclaimer: We strive to ensure that all questions and answers provided here are accurate. However, if you find any answer that seems incorrect or unclear, please feel free to suggest the correction in the comment box below. Your feedback helps us improve the quality of our content.

Q.1

Evaluate the determinant: \(\begin{vmatrix} 3 & 5 \\ 2 & 4 \end{vmatrix}\).

Answer: \( 2 \)

Q.2

Evaluate the determinant: \(\begin{vmatrix} 2 & 3 \\ 5 & 7 \end{vmatrix}\).

Answer: \(-1\)

Q.3

Find the value of: \(\begin{vmatrix} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \end{vmatrix}\).

Answer: \(0\)

Q.4

If \(\begin{vmatrix} x & 1 \\ 4 & x \end{vmatrix} = 0\), find the value of \(x\).

Answer: \(x = \pm 2\)

Q.5

Evaluate: \(\begin{vmatrix} a & b \\ c & d \end{vmatrix}\).

Answer: \(ad - bc\)

Q.6

Find the value of \(k\) such that \(\begin{vmatrix} 1 & 2 & 3 \\ 2 & k & 6 \\ 3 & 6 & 9 \end{vmatrix} = 0\).

Answer: \(\text{for all value of} k \)

Q.7

Evaluate: \(\begin{vmatrix} 3 & 1 \\ 2 & 4 \end{vmatrix}\).

Answer: \(10\)

Q.8

Find the value of: \(\begin{vmatrix} 1 & 2 \\ 2 & 4 \end{vmatrix}\).

Answer: \(0\)

Q.9

Evaluate: \(\begin{vmatrix} -1 & 3 \\ 4 & 2 \end{vmatrix}\).

Answer: \(-14\)

Q.10

If \(\begin{vmatrix} x & 2 \\ 3 & x \end{vmatrix} = 5\), find \(x\).

Answer: \(x = \pm \sqrt{11}\)

Q.11

Evaluate: \(\begin{vmatrix} 1 & 0 & 0 \\ 2 & 3 & 4 \\ 5 & 6 & 7 \end{vmatrix}\).

Answer: \(-3\)

Q.12

Evaluate: \(\begin{vmatrix} 2 & 1 & 3 \\ 1 & 0 & 2 \\ 4 & 1 & 8 \end{vmatrix}\).

Answer: \(0\)

Q.13

Find the value of \(x\) if \(\begin{vmatrix} x & 1 & 1 \\ 1 & x & 1 \\ 1 & 1 & x \end{vmatrix} = 0\).

Answer: \(x = -2, 1\)

Q.14

Evaluate: \(\begin{vmatrix} 2 & -1 & 0 \\ 1 & 3 & 2 \\ 4 & 1 & 5 \end{vmatrix}\).

Answer: \(23\)

Q.15

If \(\begin{vmatrix} a & b \\ c & d \end{vmatrix} = 4\), find \(\begin{vmatrix} 2a & 2b \\ c & d \end{vmatrix}\).

Answer: \(8\)

Q.16

Evaluate: \(\begin{vmatrix} 1 & 2 & 1 \\ 3 & 6 & 3 \\ 2 & 4 & 2 \end{vmatrix}\).

Answer: \(0\)

Q.17

Find the value of: \(\begin{vmatrix} \cos\theta & \sin\theta \\ -\sin\theta & \cos\theta \end{vmatrix}\).

Answer: \(1\)

Q.18

Evaluate: \(\begin{vmatrix} 1 & 2 & 3 \\ 0 & 1 & 4 \\ 0 & 0 & 5 \end{vmatrix}\).

Answer: \(5\)

Q.19

Find the value of \(k\) if \(\begin{vmatrix} 1 & k \\ k & 1 \end{vmatrix} = 0\).

Answer: \(k = \pm 1\)

Q.20

Evaluate: \(\begin{vmatrix} 2 & 0 & 1 \\ 3 & 1 & 2 \\ 1 & 4 & 0 \end{vmatrix}\).

Answer: \(-5\)

Q.21

If two rows of a determinant are identical, then the value of the determinant is:

Answer: \(0\)

Q.22

Evaluate: \(\begin{vmatrix} a & a & a \\ b & b & b \\ c & c & c \end{vmatrix}\).

Answer: \(0\)

Q.23

Find the value of: \(\begin{vmatrix} 1 & 1 & 1 \\ a & b & c \\ a^2 & b^2 & c^2 \end{vmatrix}\).

Answer: \((a-b)(b-c)(c-a)\)

Q.24

If \(\begin{vmatrix} x & y \\ y & x \end{vmatrix} = 0\), find the relation between \(x\) and \(y\).

Answer: \(x = \pm y\)

Q.25

Evaluate: \(\begin{vmatrix} 0 & 1 & 2 \\ 3 & 4 & 5 \\ 6 & 7 & 8 \end{vmatrix}\).

Answer: \(0\)

Q.26

If \(\begin{vmatrix} 1 & 2 \\ 3 & 4 \end{vmatrix} = -2\), find \(\begin{vmatrix} 4 & 3 \\ 2 & 1 \end{vmatrix}\).

Answer: \(-2\)

Q.27

Evaluate: \(\begin{vmatrix} 4 & 5 \\ 6 & 7 \end{vmatrix}\).

Answer: \(-2\)

Q.28

Find the value of: \(\begin{vmatrix} 1 & -1 \\ -1 & 1 \end{vmatrix}\).

Answer: \(0\)

Q.29

Evaluate: \(\begin{vmatrix} 2 & 3 & 4 \\ 1 & 2 & 3 \\ 0 & 1 & 2 \end{vmatrix}\).

Answer: \(0\)

Q.30

Find the value of \(x\) if \(\begin{vmatrix} x & 1 \\ 1 & x \end{vmatrix} = 3\).

Answer: \(x = \pm 2\)

Q.31

Evaluate: \(\begin{vmatrix} 1 & 2 & 3 \\ 3 & 6 & 9 \\ 2 & 4 & 6 \end{vmatrix}\).

Answer: \(0\)

Q.32

If \(\begin{vmatrix} a & b \\ c & d \end{vmatrix} = 7\), find \(\begin{vmatrix} a & b \\ 2c & 2d \end{vmatrix}\).

Answer: \(14\)

Q.33

Evaluate: \(\begin{vmatrix} 2 & 0 & 1 \\ 0 & 3 & 4 \\ 0 & 0 & 5 \end{vmatrix}\).

Answer: \(30\)

Q.34

Find the value of: \(\begin{vmatrix} x & x \\ x & x \end{vmatrix}\).

Answer: \(0\)

Q.35

Evaluate: \(\begin{vmatrix} 1 & 1 & 0 \\ 2 & 3 & 1 \\ 4 & 5 & 2 \end{vmatrix}\).

Answer: \(1\)

Q.36

If \(\begin{vmatrix} 1 & k \\ k & 1 \end{vmatrix} = 0\), find \(k\).

Answer: \(k = \pm 1\)

Q.37

Evaluate: \(\begin{vmatrix} \sin\theta & \cos\theta \\ -\cos\theta & \sin\theta \end{vmatrix}\).

Answer: \(1\)

Q.38

Evaluate: \(\begin{vmatrix} a & b & c \\ a & b & c \\ x & y & z \end{vmatrix}\).

Answer: \(0\)

Q.39

Find the value of: \(\begin{vmatrix} 1 & 1 & 1 \\ 1 & 2 & 3 \\ 1 & 3 & 6 \end{vmatrix}\).

Answer: \(1\)

Q.40

If \(\begin{vmatrix} a & b \\ b & a \end{vmatrix} = 0\), find the relation between \(a\) and \(b\).

Answer: \(a = \pm b\)

Q.41

Evaluate: \(\begin{vmatrix} 2 & 1 & 3 \\ 1 & 1 & 2 \\ 3 & 2 & 4 \end{vmatrix}\).

Answer: \(1\)

Q.42

Evaluate: \(\begin{vmatrix} 0 & 2 & 1 \\ 3 & 0 & 4 \\ 5 & 6 & 0 \end{vmatrix}\).

Answer: \(58\)

Q.43

If \(\begin{vmatrix} x & 2 \\ 3 & x \end{vmatrix} = 7\), find \(x\).

Answer: \(x = \pm \sqrt{13}\)

Q.44

Evaluate: \(\begin{vmatrix} 1 & 2 & 1 \\ 0 & 1 & 3 \\ 0 & 0 & 4 \end{vmatrix}\).

Answer: \(4\)

Q.45

Find the value of: \(\begin{vmatrix} a & b & c \\ b & c & a \\ c & a & b \end{vmatrix}\).

Answer: \((a+b+c)(a^2+b^2+c^2-ab-bc-ca)\)

Q.46

Evaluate: \(\begin{vmatrix} 1 & 3 & 5 \\ 2 & 4 & 6 \\ 3 & 5 & 7 \end{vmatrix}\).

Answer: \(0\)

Q.47

Evaluate the determinant of the diagonal matrix: \(\begin{vmatrix} 2 & 0 & 0 \\ 0 & 3 & 0 \\ 0 & 0 & 5 \end{vmatrix}\).

Answer: \(30\)

Q.48

Find the value of: \(\begin{vmatrix} 7 & 0 & 0 \\ 0 & -2 & 0 \\ 0 & 0 & 4 \end{vmatrix}\).

Answer: \(-56\)

Q.49

Evaluate the determinant of the anti-diagonal matrix: \(\begin{vmatrix} 0 & 0 & 3 \\ 0 & 2 & 0 \\ 1 & 0 & 0 \end{vmatrix}\).

Answer: \(-6\)

Q.50

Evaluate: \(\begin{vmatrix} 0 & 0 & 5 \\ 0 & 4 & 0 \\ 3 & 0 & 0 \end{vmatrix}\).

Answer: \(-60\)

Q.51

Find the determinant: \(\begin{vmatrix} a & 0 & 0 \\ 0 & b & 0 \\ 0 & 0 & c \end{vmatrix}\).

Answer: \(abc\)

Q.52

Evaluate: \(\begin{vmatrix} 0 & 0 & a \\ 0 & b & 0 \\ c & 0 & 0 \end{vmatrix}\).

Answer: \(-abc\)

Q.53

Find the value of: \(\begin{vmatrix} 1 & 0 & 0 & 0 \\ 0 & 2 & 0 & 0 \\ 0 & 0 & 3 & 0 \\ 0 & 0 & 0 & 4 \end{vmatrix}\).

Answer: \(24\)

Q.54

Evaluate the anti-diagonal determinant: \(\begin{vmatrix} 0 & 0 & 0 & 1 \\ 0 & 0 & 2 & 0 \\ 0 & 3 & 0 & 0 \\ 4 & 0 & 0 & 0 \end{vmatrix}\).

Answer: \(24\)

Q.55

Find the determinant: \(\begin{vmatrix} x & 0 & 0 \\ 0 & x & 0 \\ 0 & 0 & x \end{vmatrix}\).

Answer: \(x^3\)

Q.56

Evaluate: \(\begin{vmatrix} 0 & 0 & x \\ 0 & x & 0 \\ x & 0 & 0 \end{vmatrix}\).

Answer: \(-x^3\)

Q.57

If \(\begin{vmatrix} 3 & 0 & 0 \\ 0 & k & 0 \\ 0 & 0 & 2 \end{vmatrix} = 24\), find \(k\).

Answer: \(k = 4\)

Q.58

Find the value of \(a\) if \(\begin{vmatrix} 0 & 0 & a \\ 0 & 5 & 0 \\ 2 & 0 & 0 \end{vmatrix} = -40\).

Answer: \(a = 4\)

Q.59

Evaluate: \(\begin{vmatrix} 5 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & -2 \end{vmatrix}\).

Answer: \(-10\)

Q.60

Evaluate: \(\begin{vmatrix} 0 & 0 & 4 \\ 0 & -3 & 0 \\ 2 & 0 & 0 \end{vmatrix}\).

Answer: \(24\)

Q.61

Find the determinant: \(\begin{vmatrix} a & 0 & 0 \\ 0 & a & 0 \\ 0 & 0 & a \end{vmatrix}\).

Answer: \(a^3\)

Q.62

Evaluate the anti-diagonal determinant: \(\begin{vmatrix} 0 & 0 & 1 \\ 0 & 2 & 0 \\ 3 & 0 & 0 \end{vmatrix}\).

Answer: \(-6\)

Q.63

If \(\begin{vmatrix} 2 & 0 & 0 \\ 0 & 3 & 0 \\ 0 & 0 & x \end{vmatrix} = 30\), find \(x\).

Answer: \(x = 5\)

Q.64

Evaluate: \(\begin{vmatrix} 0 & 0 & 2 \\ 0 & y & 0 \\ 4 & 0 & 0 \end{vmatrix}\).

Answer: \(-8y\)

Q.65

Find the value of: \(\begin{vmatrix} p & 0 & 0 \\ 0 & q & 0 \\ 0 & 0 & r \end{vmatrix}\).

Answer: \(pqr\)

Q.66

Evaluate the anti-diagonal determinant: \(\begin{vmatrix} 0 & 0 & a \\ 0 & b & 0 \\ c & 0 & 0 \end{vmatrix}\).

Answer: \(-abc\)

Q.67

Evaluate: \(\begin{vmatrix} \sin\theta & \cos\theta \\ \cos\theta & -\sin\theta \end{vmatrix}\).

Answer: \(-1\)

Q.68

Evaluate: \(\begin{vmatrix} \cos\theta & \sin\theta \\ -\sin\theta & \cos\theta \end{vmatrix}\).

Answer: \(1\)

Q.69

Find the value of: \(\begin{vmatrix} \sin A & \cos A & 0 \\ \cos A & -\sin A & 0 \\ 0 & 0 & 1 \end{vmatrix}\).

Answer: \(-1\)

Q.70

Evaluate: \(\begin{vmatrix} \sin x & \cos x & \sin x \\ \cos x & -\sin x & \cos x \\ 0 & 0 & 1 \end{vmatrix}\).

Answer: \(-1\)

Q.71

Find the value of \(x\) if \(\begin{vmatrix} x-1 & 2 \\ 3 & x-1 \end{vmatrix} = 0\).

Answer: \(x = 1 \pm \sqrt{6}\)

Q.72

Find the value of \(x\) if \(\begin{vmatrix} x-2 & 1 \\ 4 & x-2 \end{vmatrix} = 0\).

Answer: \(x = 0, 4\)

Q.73

Evaluate: \(\begin{vmatrix} x-a & 0 \\ 0 & x-a \end{vmatrix}\).

Answer: \((x-a)^2\)

Q.74

Evaluate: \(\begin{vmatrix} x-a & x-a \\ x-a & x-a \end{vmatrix}\).

Answer: \(0\)

Q.75

Find the value of: \(\begin{vmatrix} x-1 & 1 & 1 \\ 1 & x-1 & 1 \\ 1 & 1 & x-1 \end{vmatrix}\).

Answer: \((x-2)^2(x+1)\)

Q.76

Find the value of \(x\) if \(\begin{vmatrix} x & 1 & 1 \\ 1 & x & 1 \\ 1 & 1 & x \end{vmatrix} = 0\).

Answer: \(x = 1,\,-2\)

Q.77

Evaluate: \(\begin{vmatrix} \cos x & \sin x & 0 \\ -\sin x & \cos x & 0 \\ 0 & 0 & x \end{vmatrix}\).

Answer: \(x\)

Q.78

Evaluate: \(\begin{vmatrix} x & \sin x \\ \sin x & x \end{vmatrix}\).

Answer: \(x^2 - \sin^2 x\)

Q.79

Find the value of: \(\begin{vmatrix} x-a & b \\ b & x-a \end{vmatrix}\).

Answer: \((x-a)^2 - b^2\)

Q.80

Find the value of \(x\) if \(\begin{vmatrix} x-3 & 4 \\ 4 & x-3 \end{vmatrix} = 0\).

Answer: \(x = -1, 7\)

Q.81

Evaluate: \(\begin{vmatrix} \sin^2 x & \sin x \cos x \\ \sin x \cos x & \cos^2 x \end{vmatrix}\).

Answer: \(0\)

Q.82

Evaluate: \(\begin{vmatrix} 1 & \cos x \\ \cos x & 1 \end{vmatrix}\).

Answer: \(\sin^2 x\)

Q.83

Find the value of: \(\begin{vmatrix} x-1 & x-1 & x-1 \\ x-1 & x-1 & x-1 \\ 1 & 1 & 1 \end{vmatrix}\).

Answer: \(0\)

Q.84

Evaluate: \(\begin{vmatrix} x & 0 & \sin x \\ 0 & x & \cos x \\ \sin x & \cos x & x \end{vmatrix}\).

Answer: \(x(x^2-1)\)

Q.85

Find the value of \(x\) if \(\begin{vmatrix} x & \sin x \\ \sin x & x \end{vmatrix} = 0\).

Answer: \(x = \pm \sin x\)

Q.86

Evaluate: \(\begin{vmatrix} x-a & 1 & 1 \\ 1 & x-a & 1 \\ 1 & 1 & x-a \end{vmatrix}\).

Answer: \((x-a-1)^2(x-a+2)\)

Q.87

Find the value of \(x\) if \(\begin{vmatrix} x & 2 \\ 3 & x \end{vmatrix} = 10\).

Answer: \(x = -4, 4\)

Q.88

If \(\begin{vmatrix} a & 1 \\ 2 & b \end{vmatrix} = 7\) and \(a+b=9\), find \(a\) and \(b\).

Answer: \(Answer: \(a,b=\frac{9\pm3\sqrt5}{2}\) \)

Q.89

Find the value of \(a\) if \(\begin{vmatrix} a & 3 \\ 2 & a \end{vmatrix} = 1\).

Answer: \(a = \pm \sqrt{7}\)

Q.90

If \(\begin{vmatrix} a & b \\ b & a \end{vmatrix} = 0\) and \(a \neq 0\), find \(\frac{b}{a}\).

Answer: \(\pm 1\)

Q.91

Find the value of \(k\) if \(\begin{vmatrix} 1 & k \\ k & 4 \end{vmatrix} = 3\).

Answer: \(k = 1,\,-1\)

Q.92

Evaluate: \(\begin{vmatrix} 1 & x & x^2 \\ 1 & y & y^2 \\ 1 & z & z^2 \end{vmatrix}\).

Answer: \(Answer: \((y-x)(z-x)(z-y)\)

Q.93

Evaluate: \(\begin{vmatrix} a+b & b+c & c+a \\ a & b & c \\ 1 & 1 & 1 \end{vmatrix}\).

Answer: \(a^2 + b^2 + c^2 - ab - bc - ca\)

Q.94

Find the value of: \(\begin{vmatrix} a & b & c \\ b & c & a \\ c & a & b \end{vmatrix}\).

Answer: \((a+b+c)(a^2+b^2+c^2-ab-bc-ca)\)

Q.95

Evaluate: \(\begin{vmatrix} x & 1 & 1 \\ 1 & x & 1 \\ 1 & 1 & x \end{vmatrix}\).

Answer: \((x-1)^2(x+2)\)

Q.96

Find the value of \(x\) if \(\begin{vmatrix} x & 1 & 1 \\ 1 & x & 1 \\ 1 & 1 & x \end{vmatrix} = 0\).

Answer: \(x = 1,\,-2\)

Q.97

Evaluate: \(\begin{vmatrix} 1 & a & a^2 \\ 1 & b & b^2 \\ 1 & c & c^2 \end{vmatrix}\).

Answer: \((a-b)(b-c)(c-a)\)

Q.98

Evaluate: \(\begin{vmatrix} a & a^2 & 1 \\ b & b^2 & 1 \\ c & c^2 & 1 \end{vmatrix}\).

Answer: \((a-b)(a-c)(b-c)\)

Q.99

If \(\begin{vmatrix} x-1 & 2 \\ 3 & x-1 \end{vmatrix} = 4\), find \(x\).

Answer: \(x = 3,\,-1\)

Q.100

Find the value of \(a\) if \(\begin{vmatrix} a & 4 \\ 1 & a \end{vmatrix} = 5\).

Answer: \(a = 3,\,-3\)

Q.101

Evaluate: \(\begin{vmatrix} x & y & z \\ z & x & y \\ y & z & x \end{vmatrix}\).

Answer: \((x+y+z)(x^2+y^2+z^2-xy-yz-zx)\)

Q.102

If \(\begin{vmatrix} x & y & 1 \\ y & x & 1 \\ 1 & 1 & 1 \end{vmatrix} = 0\), find the relation between \(x\) and \(y\).

Answer: \((x-y)(x-2+y)=0\)

Q.103

Evaluate: \(\begin{vmatrix} 1 & a & b \\ a & 1 & b \\ a & a & 1 \end{vmatrix}\).

Answer: \((1-a)(1+a-2ab)\)

Q.104

Find the value of \(k\) if \(\begin{vmatrix} 1 & 1 & 1 \\ 1 & k & k^2 \\ 1 & k^2 & k \end{vmatrix} = 0\).

Answer: \(k = 1, 0 , -2\)

Q.105

Evaluate: \(\begin{vmatrix} x & x+1 & x+2 \\ 1 & 1 & 1 \\ 1 & 2 & 3 \end{vmatrix}\).

Answer: \(0\)

Q.106

Find the value of \(x\) if \(\begin{vmatrix} x & x & 1 \\ x & x & 1 \\ 1 & 1 & x \end{vmatrix} = 0\).

Answer: All real \(x\)

Q.107

Evaluate: \(\begin{vmatrix} 1+i & 1-i \\ 1-i & 1+i \end{vmatrix}\).

Answer: \(4i\)

Q.108

Find the value of: \(\begin{vmatrix} i & 1 \\ -1 & i \end{vmatrix}\).

Answer: \(0\)

Q.109

Evaluate: \(\begin{vmatrix} 1 & i \\ -i & 1 \end{vmatrix}\).

Answer: \(0\)

Q.110

Find the value of \(x\) if \(\begin{vmatrix} x+i & 1 \\ 1 & x-i \end{vmatrix} = 0\).

Answer: \(x = 0\)

Q.111

Evaluate: \(\begin{vmatrix} i & 1 & 0 \\ 1 & -i & 0 \\ 0 & 0 & 1 \end{vmatrix}\).

Answer: \(0\)

Q.112

Evaluate: \(\begin{vmatrix} 1 & i & i \\ -i & 1 & i \\ -i & -i & 1 \end{vmatrix}\).

Answer: \(4\)

Q.113

Find the value of: \(\begin{vmatrix} z & \bar z \\ \bar z & z \end{vmatrix}\), where \(z=a+ib\).

Answer: \(4iab\)

Q.114

Evaluate: \(\begin{vmatrix} 1+i & 2i \\ -2i & 1-i \end{vmatrix}\).

Answer: \(-2\)

Q.115

Find the value of \(a\) if \(\begin{vmatrix} a & i \\ -i & a \end{vmatrix} = 5\).

Answer: \(a=\pm\sqrt6\)

Q.116

Evaluate: \(\begin{vmatrix} i & 1 & 1 \\ 1 & i & 1 \\ 1 & 1 & i \end{vmatrix}\).

Answer: \(-2i\)

Q.117

Find the value of \(x\) if \(\begin{vmatrix} x+i & 1 \\ 1 & x+i \end{vmatrix} = 0\).

Answer: \(x = -i \pm 1\)

Q.118

Evaluate: \(\begin{vmatrix} 1 & i & 0 \\ -i & 1 & 0 \\ 0 & 0 & i \end{vmatrix}\).

Answer: \(0\)

Q.119

Evaluate: \(\begin{vmatrix} 1+i & 1 & 1 \\ 1 & 1+i & 1 \\ 1 & 1 & 1+i \end{vmatrix}\).

Answer: \(-3-i\)

Q.120

Find the value of: \(\begin{vmatrix} i & i & i \\ 1 & 1 & 1 \\ 1 & -1 & 0 \end{vmatrix}\).

Answer: \(2i\)

Q.121

Evaluate: \(\begin{vmatrix} 1 & i & -i \\ -i & 1 & i \\ i & -i & 1 \end{vmatrix}\).

Answer: \(4\)

Q.122

Find the value of \(a\) if \(\begin{vmatrix} a+i & 1 \\ 1 & a-i \end{vmatrix} = 1\).

Answer: \(a = 0\)

Q.123

Evaluate: \(\begin{vmatrix} z & i \\ -i & \bar z \end{vmatrix}\), where \(z=a+ib\).

Answer: \(a^2+b^2-1\)

Q.124

Find the value of: \(\begin{vmatrix} 1+i & 0 & 0 \\ 0 & 1-i & 0 \\ 0 & 0 & i \end{vmatrix}\).

Answer: \(2i\)

Q.125

Evaluate: \(\begin{vmatrix} i & 1 & 1 \\ 1 & i & -1 \\ 1 & -1 & i \end{vmatrix}\).

Answer: \(-4i\)

Q.126

Find the value of \(x\) if \(\begin{vmatrix} x+i & i \\ -i & x-i \end{vmatrix} = 0\).

Answer: \(x = 0\)

Q.127

Find the area of the triangle with vertices \(A(1,2)\), \(B(3,6)\), and \(C(5,2)\) using determinants.

Answer: \(8\) square units

Q.128

Find the area of the triangle formed by the points \((0,0)\), \((4,0)\), and \((0,6)\).

Answer: \(12\) square units

Q.129

Using determinants, check whether the points \((1,2)\), \((2,4)\), and \((3,6)\) are collinear.

Answer: Yes, the points are collinear

Q.130

Find the value of \(k\) such that the area of the triangle formed by \((1,1)\), \((2,3)\), and \((3,k)\) is zero.

Answer: \(k = 5\)

Q.131

Find the area of the triangle with vertices \((-1,2)\), \((3,4)\), and \((2,-2)\).

Answer: \(14\) square units

Q.132

Show that the points \((2,1)\), \((4,3)\), and \((6,5)\) lie on a straight line using determinants.

Answer: Determinant value is zero, hence collinear

Q.133

Find the value of \(k\) if the area of the triangle formed by \((0,0)\), \((k,4)\), and \((2,6)\) is 10 square units.

Answer: \(k = 1 \text{ or } 5\)

Q.134

Find the area of the triangle formed by the intercepts of the line \(2x+3y=6\) with the coordinate axes.

Answer: \(3\) square units

Q.135

Using determinants, check whether the points \((1,-1)\), \((3,1)\), and \((5,3)\) are collinear.

Answer: Yes, the points are collinear

Q.136

Find the area of the triangle formed by the points \((2,3)\), \((4,7)\), and \((6,3)\).

Answer: \(8\) square units

Q.137

Find the value of \(k\) if the points \((1,2)\), \((3,k)\), and \((5,8)\) are collinear.

Answer: \(k = 5\)

Q.138

Find the area of the triangle formed by the points \((0,4)\), \((3,0)\), and \((6,4)\).

Answer: \(12\) square units

Q.139

Using determinants, check whether the points \((2,5)\), \((4,9)\), and \((6,13)\) lie on the same straight line.

Answer: Yes, they are collinear

Q.140

Find the area of the triangle with vertices \((1,1)\), \((2,4)\), and \((5,1)\).

Answer: \(6\) square units

Q.141

Find the value of \(k\) if the area of the triangle formed by \((1,k)\), \((2,3)\), and \((4,7)\) is zero.

Answer: \(k = 1\)

Q.142

Find the area of the triangle formed by the points \((-2,0)\), \((2,0)\), and \((0,4)\).

Answer: \(8\) square units

Q.143

Using determinants, check whether the points \((0,0)\), \((1,2)\), and \((2,5)\) are collinear.

Answer: No, they are not collinear

Q.144

Find the area of the triangle formed by the points \((1,3)\), \((3,1)\), and \((5,3)\).

Answer: \(4\) square units

Q.145

Find the value of \(k\) if the points \((2,k)\), \((4,6)\), and \((6,10)\) are collinear.

Answer: \(k = 2\)

Q.146

Find the area of the triangle formed by the points \((0,2)\), \((3,6)\), and \((6,2)\).

Answer: \(12\) square units

Q.147

Using determinants, show that the points \((1,4)\), \((2,6)\), and \((3,8)\) lie on a straight line.

Answer: Determinant value is zero

Q.148

Find the area of the triangle formed by the points \((2,1)\), \((4,5)\), and \((6,1)\).

Answer: \(8\) square units

Q.149

Find the value of \(k\) if the area of the triangle formed by \((k,1)\), \((2,3)\), and \((4,5)\) is zero.

Answer: \(k = 0\)

Q.150

Find the area of the triangle formed by the points \((1,0)\), \((4,4)\), and \((7,0)\) using determinants.

Answer: \(12\) square units
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