3 and 4 .Determinants and Matrices
medium

જો $A=\left[\begin{array}{rr}1 & 0 \\ 0 & -1\end{array}\right]$ અને  $B=\left[\begin{array}{ll}0 & 1 \\ 1 & 0\end{array}\right],$  હોય, તો $AB$ અને $BA$ શોધો તથા બતાવો કે, $\mathrm{AB} \neq \mathrm{BA}$.

Option A
Option B
Option C
Option D

Solution

This does not mean that $\mathrm{AB} \neq \mathrm{BA}$ for every pair of matrices $\mathrm{A}, \mathrm{B}$ for which $\mathrm{AB}$ and $\mathrm{BA}$, are defined. For instance,

If $A=\left[\begin{array}{ll}1 & 0 \\ 0 & 2\end{array}\right], B=\left[\begin{array}{ll}3 & 0 \\ 0 & 4\end{array}\right],$ then $A B=B A=\left[\begin{array}{ll}3 & 0 \\ 0 & 8\end{array}\right]$

Observe that multiplication of diagonal matrices of same order will be commutative.

Standard 12
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.