NCERT Solutions class 12 Maths Exercise 4.4 Ch 4 Determinants


NCERT Solutions for Class 12 Maths Exercise 4.4 Chapter 4 Determinants – FREE PDF Download

NCERT Solutions for Class 12 Maths Chapter 4 – Determinants is a sure-shot way of obtaining the complete marks in the particular chapter for Board Exam 2019- 2020. CoolGyan provides you with Free PDF download of the same solved by Expert Teachers as per NCERT (CBSE) Book guidelines. They provide the students with precise and to the point answers which fetch very good marks in Board Exams. Download today the NCERT CBSE Solutions for Class 12 Maths Chapter 4 – Determinants to achieve your goal score. Class 12 Maths Chapter 4 – Determinants solved by Expert Teachers as per NCERT (CBSE) Book guidelines.

NCERT Solutions for Class 12 Maths Chapter 4 – Determinants



1. Write minors and cofactors of the elements of the following determinants:

(i) 

(ii) 

Ans. (i) Let  

M11 = Minor of  and A11 = 

M12 = Minor of  and A12 = 

M21 = Minor of a21=|4|=4a21=|−4|=−4  and A21 = 

M22 = Minor of  and A22 = 

(ii) Let 

M11 = Minor of  and A11 = 

M12 = Minor of  and A12 = 

M21 = Minor of  and A21 = 

M22 = Minor of  and A22 = 


2. Write minors and cofactors of the elements of the following determinants:

 

(i) 

(ii) 

Ans. (i) Let  

M11 = Minor of  and A11 = 

M12 = Minor of  and A12 = 

M13 = Minor of  and A13 = 

M21 = Minor of  and A21 = 

M22 = Minor of  and A22 = 

M23 = Minor of  and A23 = 

M31 = Minor of  and A31 = 

M32 = Minor of  and A32 = 

M33 = Minor of  and A31 = 

(ii) Let 

M11 = Minor of  and A11 = 

M12 = Minor of  and A12 = 

M13 = Minor of  and A13 = 

M21 = Minor of  and A21 = 

M22 = Minor of  and A22 = 

M23 = Minor of  and A23 = 

M31 = Minor of  and A31 = 

M32 = Minor of  and A32 = 

M33 = Minor of  and A31 = 


3. Using cofactors of elements of second row, evaluate:

 

Ans. Elements of second row of  are  

A21 = Cofactor of  = 

A22 = Cofactor of  = 

A23 = Cofactor of  = 

  = 


4. Using cofactors of elements of third column, evaluate:

 

Ans. Elements of third column of  are  

A13 = Cofactor of  = 

A23 = Cofactor of  = 

A33 = Cofactor of  = 

  = 

 = 

 = 

 = 

 = 


5. If  and  is cofactor of  then value of  is given by:

 

(A) 

(B) 

(C) 

(D) 

Ans. Option (D) is correct.