MCQ
If $A = \left[ {\begin{array}{*{20}{c}}1&2\\0&1\end{array}} \right],$then ${A^n} = $
  • $\left[ {\begin{array}{*{20}{c}}1&{2n}\\0&1\end{array}} \right]$
  • B
    $\left[ {\begin{array}{*{20}{c}}2&n\\0&1\end{array}} \right]$
  • C
    $\left[ {\begin{array}{*{20}{c}}1&{2n}\\0&{ - 1}\end{array}} \right]$
  • D
    $\left[ {\begin{array}{*{20}{c}}1&{2n}\\1&0\end{array}} \right]$

Answer

Correct option: A.
$\left[ {\begin{array}{*{20}{c}}1&{2n}\\0&1\end{array}} \right]$
a
(a) ${A^2} = \left[ {\begin{array}{*{20}{c}}1&2\\0&1\end{array}} \right]\,\left[ {\begin{array}{*{20}{c}}1&2\\0&1\end{array}} \right] = \left[ {\begin{array}{*{20}{c}}1&4\\0&1\end{array}} \right]$ and ${A^3} = {A^2}A$.

= $\left[ {\,\begin{array}{*{20}{c}}1&4\\0&1\end{array}\,} \right]\,\,\left[ {\,\begin{array}{*{20}{c}}1&2\\0&1\end{array}\,} \right] = \left[ {\,\begin{array}{*{20}{c}}1&6\\0&1\end{array}\,} \right]$ and so on.

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

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $x = a{\rm{ }}\left( {\cos t + \log \tan {t \over 2}} \right)\,,y = a\sin t,$ then ${{dy} \over {dx}} = $
If $2x = {y^{\frac{1}{5}}} + {y^{ - \frac{1}{5}}}$ and $(x^2 -1) \frac{{{d^2}y}}{{d{x^2}}} + \lambda x\frac{{dy}}{{dx}} + ky = 0$ , then $ \lambda + k$ is equal to
The relation R = {(1, 1), (2, 2), (3, 3)} on the set {1, 2, 3} is:
What is the length of the longer diagonal of the parallelogram constructed on $5\vec{\text{a}}+2\vec{\text{b}}$ and $\vec{\text{a}}-3\vec{\text{b}}$ if it is given that $|\vec{\text{a}}|=2\sqrt{2},\big|\vec{\text{b}}\big|=3$ and the angle between $\vec{\text{a}}$ and $\vec{\text{b}}$ is $\frac{\pi}{4}$?
The values of the constants a, b and for which the function $\text{f(x)}=\begin{cases}(1+\text{ax})^{\frac{1}{\text{x}}},&\text{x}>0\\\text{b},&\text{x}=0\\\frac{(\text{x}+\text{c})^{\frac{1}{2}}-1}{(\text{x}+1)^{\frac{1}{2}}-1},&\text{x}>0\end{cases}$ may be continuous at x = 0, are:
The vectors $\vec{\text{a}}$ and $\vec{\text{b}}$ satisfy the equation $2\vec{\text{a}}+\vec{\text{b}}=\vec{\text{p}}$ and $\vec{\text{a}}+2\vec{\text{b}}=\vec{\text{q}},$ where $\vec{\text{p}}=\hat{\text{i}}+\hat{\text{j}}$ and $\vec{\text{q}}=\hat{\text{i}}-\hat{\text{j}}.$ If $\theta$ is the angle between $\vec{\text{a}}$ and $\vec{\text{b}},$ then:
If $\sin\text{y}=\text{x}\cos(\text{a}+\text{y}),$ then $\frac{\text{dy}}{\text{dx}}$ is equal to:
The distance of the point P(a, b, c) from the x-axis is:
The function $f(x)=x-\frac{1}{x}, x \in R, x \neq 0$ is
A special lottery is to be held to select a student who will live in the only deluxe room in a hostel. There are $100$ Year$\text{-III,} 150$ Year$-II$ and $200$ Year$-I$ students who applied. Each Year$-III\ 's$ name is placed in the lottery $3$ times; each Year$-II\ 's$ name$, 2$ times and Year$-I\ 's$ name$, 1$ time. What is the probability that a Year$-III\ 's$ name will be chosen?