3 and 4 .Determinants and Matrices
easy

Find $\mathrm{AB},$ if $\mathrm{A}=\left[\begin{array}{rr}0 & -1 \\ 0 & 2\end{array}\right]$ and $\mathrm{B}=\left[\begin{array}{ll}3 & 5 \\ 0 & 0\end{array}\right]$.

A

$\left[ {\begin{array}{*{20}{l}}
  0&0 \\ 
  0&0 
\end{array}} \right]$

B

$\left[ {\begin{array}{*{20}{l}}
  0&0 \\ 
  0&0 
\end{array}} \right]$

C

$\left[ {\begin{array}{*{20}{l}}
  0&0 \\ 
  0&0 
\end{array}} \right]$

D

$\left[ {\begin{array}{*{20}{l}}
  0&0 \\ 
  0&0 
\end{array}} \right]$

Solution

We have $A B=\left[\begin{array}{rr}0 & -1 \\ 0 & 2\end{array}\right]\left[\begin{array}{ll}3 & 5 \\ 0 & 0\end{array}\right]=\left[\begin{array}{ll}0 & 0 \\ 0 & 0\end{array}\right]$

Thus, if the product of two matrices is a zero matrix, it is not necessary that one of the matrices is a zero matrix.

Standard 12
Mathematics

Similar Questions

Start a Free Trial Now

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