OP Malhotra Determinants S.Chand ISC Class-12 Maths Solutions Ch-5

OP Malhotra Determinants S.Chand ISC Class-12 Maths Solutions Ch-5. Step by step Solutions of OP Malhotra SK Gupta, Anubhuti Gangal S.Chand ISC Class-12 Mathematics with Exe-5(a), Exe-5(b), Exe-5(c), Exe-5(d), Self Revision and Chapter Test Questions. Visit official Website CISCE for detail information about ISC Board Class-12 Mathematics.

OP Malhotra Determinants S.Chand ISC Class-12 Maths Solutions Ch-5

Class: 12th
Subject: Mathematics
Chapter  : Ch-5 Determinants of Section -A
Board ISC
Writer  OP Malhotra, SK Gupta, Anubhuti Gangal
Publications S.Chand Publications 2020-21

-: Included Topics :- 

Exe-5(a)

Exe-5(b)

Exe-5(c)

Exe-5(d)

Self Revision

Chapter Test


OP Malhotra Determinants S.Chand ISC Class-12 Maths Solutions Ch-5

Determinant :

Determinant is the numerical value of the square matrix. So, to every square matrix A = [aij] of order n, we can associate a number (real or complex) called determinant of the square matrix A. It is denoted by det A or |A|.
Note :-

  • Read |A| as determinant A not absolute value of A.
  • Determinant gives numerical value but matrix do not give numerical value.
  • A determinant always has an equal number of rows and columns, i.e. only square matrix have determinants.

Exe-5(a)

OP Malhotra Determinants S.Chand ISC Class-12 Maths Solutions Ch-5

Question 1:

Evaluate the following determinants :

(i) …………………….

………………..

Question 2:

Prove that :

……………….

Question 3:

……………………

…………………….

………………………

Question 5:

Determine the value of k for which ………..


Minor :

Minor of an element ay of a determinant, is a determinant obtained by deleting the ith row and jth column in which element ay lies. Minor of an element aij is denoted by Mij.
Note: Minor of an element of a determinant of order n(n ≥ 2) is a determinant of order (n – 1).

Cofactor :

Cofactor of an element aij of a determinant, denoted by Aij or Cij is defined as Aij = (-1)i+j Mij, where Mij is a minor of an element aij.


Exe-5(b)

OP Malhotra Determinants S.Chand ISC Class-12 Maths Solutions Ch-5

Question 1:

Write minors and cofactors of elements of determinant …….

Question 2:

Write down the minors of -2 and 4 in ……………….

Question 3:

………………..

…………………..

………………….

…………………..

Question 12:

If one root of ………………… = 0


Singular and non-singular Matrix :

If the value of determinant corresponding to a square matrix is zero, then the matrix is said to be a singular matrix, otherwise it is non-singular matrix, i.e. for a square matrix A, if |A| ≠ 0, then it is said to be a non-singular matrix and of |A| = 0, then it is said to be a singular matrix.
Theorems.

  •  If A and B are non-singular matrices of the same order, then AB and BA are also non-singular matrices of the same order.
  • The determinant of the product of matrices is equal to the product of their respective determinants, i.e. |AB| = |A||B|, where A and B are a square matrix of the same order.

Exe-5(c)

OP Malhotra Determinants S.Chand ISC Class-12 Maths Solutions Ch-5

Question 1:

Find the area of the triangle whose vertices are :

(i)….

(ii) …….

Question 2:

Using determinants, prove that the following points are collinear

(i)….

(ii) …….

Question 3:

…………………..

…………………

Question 5:

If (x, y), (a, 0), (0, b) are collinear, then using determinant prove that ……………… = 1


Adjoint of a Matrix :

The adjoint of a square matrix ‘A’ is the transpose of the matrix which obtained by cofactors of each element of a determinant corresponding to that given matrix. It is denoted by adj(A).
In general, adjoint of a matrix A = [aij]n×n is a matrix [Aji]n×n, where Aji is a cofactor of element aji.


Exe-5(d)

OP Malhotra Determinants S.Chand ISC Class-12 Maths Solutions Ch-5

Question 1:

(a) without evaluate problems (i) to (x) state why each statement is true.

……………………..

(b) Without actually …………………….

Question 2:

Without expanding the determinants show that…………………

Question 3:

…………………..

……………………..

……………………..

Question 28:

Using properties of determinants ……………….. following determinants.

……………….


Properties of Determinants :

To find the value of the determinant, we try to make the maximum possible zero in a row (or a column) by using properties given below and then expand the determinant corresponding that row (or column).
Following are the various properties of determinants:

 1- The value of the determinant remains unchanged if the rows and columns of a determinant are interchanged.

 2- If any two rows (or columns) of determinants are interchanged, then sign of determinants changes.

 3- If any two rows or columns of a determinant are equal or identical, then the value of the determinant is 0.

 4- If each element of a row or a column is multiplied by a constant value k, then the value of the determinant originally obtained is multiplied with k.


Self Revision

OP Malhotra Determinants S.Chand ISC Class-12 Maths Solutions Ch-5

Question 1:

Show that the value of the following determinant is negative, if a, b and c are positive  and unequal ……..

Question 2:

Use properties of determinant to solve for x :

………………….

…………………

Question 3:

………………….

…………………

…………………..

Question 18:

Using properties of determinants, prove that …………………..


Chapter Test

OP Malhotra Determinants S.Chand ISC Class-12 Maths Solutions Ch-5

Question 1:

(i) If ………………  then find

(ii) Find …………………..

(iii) Write the value ………………….

Question 2:

If A ………….

Question 3:

…………………….

…………………….

…………………….

Question 10:

Using properties …………………..

Question 11:

……………………

-: End of Determinants OP Malhotra S. Chand ISC Class-12 Maths Chapter-5 Solution :-

Return to :-  OP Malhotra S. Chand ISC Class-12 Maths Solutions


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