3 and 4 .Determinants and Matrices
easy

If $A = \left[ {\begin{array}{*{20}{c}}0&1 \\ 1&0\end{array}} \right],$then ${A^4}$=

A

$\left[ {\begin{array}{*{20}{c}}1&0 \\ 0&1\end{array}} \right]$

B

$\left[ {\begin{array}{*{20}{c}}1&1 \\ 0&0\end{array}} \right]$

C

$\left[ {\begin{array}{*{20}{c}}0&0 \\ 1&1\end{array}} \right]$

D

$\left[ {\begin{array}{*{20}{c}}0&1 \\1&0\end{array}} \right]$

Solution

(a) We have $A = \left[ {\begin{array}{*{20}{c}}0&1\\1&0\end{array}} \right]$

$\therefore$ ${A^2} = \left[ {\begin{array}{*{20}{c}}0&1\\1&0\end{array}} \right]\,\,\left[ {\begin{array}{*{20}{c}}0&1\\1&0\end{array}} \right] = \left[ {\begin{array}{*{20}{c}}1&0\\0&1\end{array}} \right] = {I_2}$

$\therefore$ ${A^4} = {A^2}.{A^2} = {I_2}.{I_2} = {I_2} = \left[ {\begin{array}{*{20}{c}}1&0\\0&1\end{array}} \right]$.

Standard 12
Mathematics

Similar Questions

Start a Free Trial Now

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