Check sibling questions
Class 12
Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

Let A = [π‘Žπ‘–π‘—] be a square matrix of order 3Γ—3 and |A|= -7. Find the value of
π‘Ž 11 𝐴 21 + π‘Ž 12 𝐴 22 + π‘Ž 13 𝐴 23Β  where 𝐴 𝑖𝑗 is the cofactor of element π‘Ž 𝑖j

Let A = [aij] be a square matrix of order 3Γ—3 and |A|= -7. Find value

Β 

This video is only available for Teachoo black users

Introducing your new favourite teacher - Teachoo Black, at only β‚Ή83 per month


Transcript

Question 6 Let A = [π‘Žπ‘–π‘—] be a square matrix of order 3 Γ— 3 and |A|= βˆ’7. Find the value of π‘Ž11 𝐴21 + π‘Ž12 𝐴22 + π‘Ž13 𝐴23 where 𝐴𝑖𝑗 is the cofactor of element π‘Žπ‘–j We know that ο»ΏIf elements of a row (or column) are multiplied with cofactors of any other row (or column), then their sum is zero Thus, π‘Ž11 𝐴21 + π‘Ž12 𝐴22 + π‘Ž13 𝐴23 = 0

Davneet Singh's photo - Teacher, Engineer, Marketer

Made by

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.