Check sibling questions

Ex 4.5, 2 - Find adjoint of matrix - Chapter 4 Determinants - Ex 4.5

Ex 4.5, 2 - Chapter 4 Class 12 Determinants - Part 2
Ex 4.5, 2 - Chapter 4 Class 12 Determinants - Part 3

Get live Maths 1-on-1 Classs - Class 6 to 12


Transcript

Ex 4.5, 2 Find adjoint of each of the matrices. 1 1 2 2 3 5 2 0 1 Let A = 1 1 2 2 3 5 2 0 1 adj A = A11 A21 A31 A12 A22 A32 A13 A23 A33 Step 1: Cacluating minors M11 = 3 5 0 1 = 3(1) 0(5) = 3 0 = 3 M12 = 2 5 2 1 = 2 ( 10) = 2 + 10 = 12 M13 = 2 3 2 0 = 0 ( 6) = 0 + 6 = 6 M21 = 1 2 0 1 = 1 (0) = 1 + 0 = 1 M22 = 1 2 2 1 = 1 (-2)2 = 1 + 4 = 5 M23 = 1 1 2 0 = 0 ( 2) ( 1) = 0 (2) = 2 M31 = 1 2 3 5 = 5 ( 1) 6 = 5 6 = 11 M32 = 1 2 2 5 = 5 4 = 1 M33 = 1 1 2 3 = 3 ( 2) = 3 + 2 = 5 Step 2: Calculating adjoint A11 = ( 1) 1+1 . M11 = ( 1)2 . 3 = 3 A12 = ( 1) 1+2 . M12 = ( 1) 3 . (12) = 1 (12) = 12 A13 = ( 1) 1+3 . M13 = ( 1) 4 . ( 6) = 1(6) = 6 A21 = ( 1) 2+1 . M21 = ( 1) 3 . (-1) = -1(-1) = 1 A22 = ( 1) 2+2 . M22 = ( 1) 4 . (5)= 1(5) = 5 A23 = ( 1) 2+3 . M23 = ( 1) 5 . ( 2) = 1 ( 2) = 2 A31 = ( 1) 3+1 . M31 = ( 1) 4 . ( 11) = 1 ( 11) = 11 A32 = ( 1) 3+2 . M32 = ( 1) 5 . (1) = ( 1) (1) = 1 A33 = ( 1) 3+3 . M33 = ( 1)6 . ( 5) = 1 (5) = 5 Step 3: Calculating adjoint Hence, adj A = A11 A21 A31 A12 A22 A32 A13 A23 A33 = 3 1 11 12 5 1 6 2 5

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.