
Get live Maths 1-on-1 Classs - Class 6 to 12
Examples
Example 2
Example 3 Important
Example 4
Example 5 Important
Example 6
Example 7
Example 8
Example 9
Example 10
Example 11 Important
Example 12
Example 13 Important You are here
Example 14
Example 15
Example 16 Important
Example 17
Example 18 Important
Example 19
Example 20 Important
Example 21
Example 22 Important
Example 23
Example 24 Important
Example 25 Important
Example 26 Important
Example 27 Important
Example 28
Last updated at March 30, 2023 by Teachoo
Example 13 If A = [■8(1&−2&[email protected]−4&2&5)] and B = [■8(2&[email protected]&[email protected]&1)] then find AB, BA . Show that AB ≠ BA AB =[■8(1&−2&[email protected]−4&2&5)]_(2 × 3 ) [■8(2&[email protected]&[email protected]&1)]_(3 × 2) = [■8(1 × 2+(−2) × 4+3 × 2&1 × 3+(−2) × 5+3 × [email protected]−4 × 2+2 × 4+5 × 2&−4 × 3+2 × 5+5 × 1)]_(2 × 2 ) = [■8(2−8+6&3−[email protected]−8+8+10&−12+10+5)] = [■8(0&−[email protected]&3)] . BA = [■8(2&[email protected]&[email protected]&1)]_(3 × 2) [■8(1&−2&[email protected]−4&2&5)]_(2 × 3) = [■8(2 × 1+3 × (−4)&2 × (−2)+3 × 2&2 × 3+3 × [email protected] × 1+5 × (−4)&4 × (−2)+5 × 2&4 × 3+5 × [email protected] × 1+1 × (−4)&2 × (−2)+1 × 2&2 × 3+1 × 5)]_(3 × 3 ) = [■8(2−12&−4+6&[email protected]−20&−8+10&[email protected]−4&−4+2&6+5)] = [■8(−10&2&[email protected]−16&2&[email protected]−2&−2&11)] ≠ AB Hence AB ≠ BA