NCERT solutions for Mathematics [English] Class 12 chapter 4 - Determinants [Latest edition]

Evaluate the determinant.

`|(2,4),(-5, -1)|`

Evaluate the determinant.

`|(cos theta, -sin theta),(sin theta, cos theta)|`

Evaluate the determinant.

`|(x^2-x+1, x -1),(x+1, x+1)|`

If A = `[(1,2),(4,2)]` then show that |2A| = 4|A|

If A=`[(1,0,1),(0,1,2),(0,0,4)]` then show that `|3A| = 27|A|`

Evaluate the determinant.

`|(3,-1,-2),(0,0,-1),(3,-5,0)|`

Evaluate the determinant.

`|(3,-4,5),(1,1,-2),(2,3,1)|`

Evaluate the determinant.

`|(0,1,2),(-1,0,-3),(-2,3,0)|`

Evaluate the determinant.

`|(2,-1,-2),(0,2,-1),(3,-5,0)|`

If A  = `[(1,1,-2),(2,1,-3),(5,4,-9)]`, Find |A|

Find values of x, if ` |(2,4),(5,1)|=|(2x, 4), (6,x)|`

Find values of x, if `|[2,3],[4,5]|=|[x,3],[2x,5]|`

If `|(x, 2),(18, x)| = |(6,2),(18,6)|`, then x is equal to ______.

Find the area of a triangle with vertices at the point given in the following:

(1, 0), (6, 0), (4, 3)

Find the area of a triangle with vertices at the point given in the following:

(2, 7), (1, 1), (10, 8)

Find the area of a triangle with vertices at the point given in the following:

(−2, −3), (3, 2), (−1, −8)

Show that points A (a, b + c), B (b, c + a), C (c, a + b) are collinear.

Find values of k if area of triangle is 4 square units and vertices are (k, 0), (4, 0), (0, 2)

Find values of k if area of triangle is 4 square units and vertices are (−2, 0), (0, 4), (0, k)

Find equation of line joining (1, 2) and (3, 6) using the determinant.

Find equation of line joining (3, 1) and (9, 3) using determinant.

If area of triangle is 35 square units with vertices (2, −6), (5, 4), and (k, 4), then k is ______.

Write Minors and Cofactors of the elements of following determinants:

`|(2,-4),(0,3)|`

Write Minors and Cofactors of the elements of following determinants:

`|(a,c),(b,d)|`

Write Minors and Cofactors of the elements of following determinants:

`|(1,0,0),(0,1,0),(0,0,1)|`

Write Minors and Cofactors of the elements of following determinants:

`|(1,0,4),(3,5,-1),(0,1,2)|`

Using Cofactors of elements of second row, evaluate `triangle = |(5,3,8),(2,0,1),(1,2, 3)|`

Using Cofactors of elements of third column, evaluate `triangle = |(1,x,yz),(1,y,zx),(1,z,xy)|`

If `triangle = |(a_11,a_12,a_13),(a_21,a_22,a_23),(a_31,a_32,a_33)|` and A_ij is Cofactors of a_ij, then value of Δ is given by ______.

Find the adjoint of the matrices.

`[(1,2),(3,4)]`

Find the adjoint of the matrices.

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

Verify A (adj A) = (adj A) A = |A|I.

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

Verify A (adj A) = (adj A) A = |A|I.

`[(1,-1,2),(3,0,-2),(1,0,3)]`

Find the inverse of the matrices (if it exists).

`[(2,-2),(4,3)]`

Find the inverse of the matrices (if it exists).

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

Find the inverse of the matrices (if it exists).

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

Find the inverse of the matrices (if it exists).

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

Find the inverse of the matrices (if it exists).

`[(2,1,3),(4,-1,0),(-7,2,1)]`

Find the inverse of the matrices (if it exists).

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

Find the inverse of the matrices (if it exists).

`[(1,0,0),(0, cos alpha, sin alpha),(0, sin alpha, -cos alpha)]`

Let `A =[(3,7),(2,5)] and B = [(6,8),(7,9)]`. Verify that `(AB)^(-1) = B^(-1)A^(-1).`

If A = `[(3,1),(-1,2)]` show that A² – 5A + 7I = O. Hence, find A^–1.

For the matrix A = `[(3,2),(1,1)]` find the numbers a and b such that A² + aA + bI = O.

For the matrix A = `[(1,1,1),(1,2,-3),(2,-1,3)]` show that A³ − 6A² + 5A + 11 I = O. Hence, find A^−1.

If A = `[(2,-1,1),(-1,2,-1),(1,-1,2)]` verify that A³ − 6A² + 9A − 4I = O and hence find A⁻¹

Let A be a nonsingular square matrix of order 3 × 3. Then |adj A| is equal to ______.

If A is an invertible matrix of order 2, then det (A⁻¹) is equal to ______.

Examine the consistency of the system of equations.

x + 2y = 2

2x + 3y = 3

Examine the consistency of the system of equations.

2x − y = 5

x + y = 4

Examine the consistency of the system of equations.

x + 3y = 5

2x + 6y = 8

Examine the consistency of the system of equations.

x + y + z = 1

2x + 3y + 2z = 2

ax + ay + 2az = 4

Examine the consistency of the system of equations.

3x − y − 2z = 2

2y − z = −1

3x − 5y = 3

Examine the consistency of the system of equations.

5x − y + 4z = 5

2x + 3y + 5z = 2

5x − 2y + 6z = −1

Solve system of linear equations, using matrix method.

5x + 2y = 4

7x + 3y = 5

Solve system of linear equations, using matrix method.

2x – y = –2

3x + 4y = 3

Solve system of linear equations, using matrix method.

4x – 3y = 3

3x – 5y = 7

Solve system of linear equations, using matrix method.

5x + 2y = 3

3x + 2y = 5

Solve system of linear equations, using matrix method.

2x + y + z = 1

x – 2y – z =` 3/2`

3y – 5z = 9

Solve the system of linear equations using the matrix method.

x − y + z = 4

2x + y − 3z = 0

x + y + z = 2

Solve the system of linear equations using the matrix method.

2x + 3y + 3z = 5

x − 2y + z = −4

3x − y − 2z = 3

Solve the system of linear equations using the matrix method.

x − y + 2z = 7

3x + 4y − 5z = −5

2x − y + 3z = 12

If A = `[(2,-3,5),(3,2,-4),(1,1,-2)]` find A⁻¹. Using A⁻¹ solve the system of equations

2x – 3y + 5z = 11
3x + 2y – 4z = – 5
x + y – 2z = – 3

The cost of 4 kg onion, 3 kg wheat and 2 kg rice is Rs 60. The cost of 2 kg onion, 4 kg wheat and 6 kg rice is Rs 90. The cost of 6 kg onion 2 kg wheat and 3 kg rice is Rs 70. Find cost of each item per kg by matrix method.

Prove that the determinant `|(x,sin theta, cos theta),(-sin theta, -x, 1),(cos theta, 1, x)|` is independent of θ.

Evaluate `|(cos alpha cos beta, cos alpha sin beta, -sin alpha),(-sin beta, cos beta, 0),(sin alpha cos beta, sin alpha sin beta,cos alpha )|`

If `A^(-1) =[(3,-1,1),(-15,6,-5),(5,-2,2)]` and `B = [(1,2,-2),(-1,3,0),(0,-2,1)]`  find  `(AB)^(-1)`

Let A = `[(1,-2,1),(-2,3,1),(1,1,5)]` verify that

1. [adj A]^–1 = adj (A^–1)
2. (A^–1)^–1 = A

Evaluate `|(x, y, x+y),(y, x+y, x),(x+y, x, y)|`

Evaluate `|(1,x,y),(1,x+y,y),(1,x,x+y)|`

Solve the system of the following equations:

`2/x+3/y+10/z = 4`

`4/x-6/y + 5/z = 1`

`6/x + 9/y - 20/x = 2`

If x, y, z are nonzero real numbers, then the inverse of matrix A = `[(x,0,0),(0,y,0),(0,0,z)]` is ______.

Let A = `[(1, sin theta, 1),(-sin theta,1,sin 1),(-1, -sin theta, 1)]` where 0 ≤ θ≤ 2π, then ______.