MCQ
Matrix ${A_\lambda } = \left[ {\begin{array}{*{20}{c}}
  \lambda &{\lambda  - 1} \\ 
  {\lambda  - 1}&\lambda  
\end{array}} \right],\lambda  \in N$ then the value of $\left| {{A_1}} \right| + \left| {{A_2}} \right| + \left| {{A_3}} \right| + ....... + \left| {{A_{300}}} \right|$ is
  • A
    $(299)^2$
  • $(300)^2$
  • C
    $(150)^2$
  • D
    $(301)^2$

Answer

Correct option: B.
$(300)^2$
b
$\left| {{{\rm{A}}_\lambda }} \right| = \left| {\begin{array}{*{20}{c}}
\lambda &{\lambda  - 1}\\
{\lambda  - 1}&\lambda 
\end{array}} \right| = {\lambda ^2} - {[\lambda  - 1)^2}$

$ = 2\lambda  - 1$

$\therefore \left| {{{\rm{A}}_1}} \right| + \left| {{{\rm{A}}_2}} \right| + \left| {{{\rm{A}}_3}} \right| +  \ldots . + \left| {{{\rm{A}}_{300}}} \right|$

$=1+3^{2}+5+\ldots . .+599 $ 

$= \frac{300}{2}(1+599)=(300)^{2} $

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

Let $f(x) = \frac{{{x^2} - 4}}{{{x^2} + 4}}$ for $|x|\; > 2$, then the function $f:( - \infty ,\; - 2] \cup [2,\;\infty ) \to ( - 1,\;1)$ is
Two persons $'A'$ and $'B'$ have respectively $n + 1$ and $n$ coins which they toss simultaneously. Then the probability that $A$ will have more heads than $B$ is
The solution of $y\,dx - xdy + 3{x^2}{y^2}{e^{{x^3}}}dx = 0$ is
If $\frac{{dy}}{{dx}} + y\tan x = \sin 2x$ and $y(0)\,=1$ , then $y(\pi)$ is equal to
The area of the region bounded by the ellipse $\frac{\text{x}^2}{25}+\frac{\text{y}^2}{16}=1$ is:
  1. $20\pi\text{ sq}.\text{units}$
  2. $20^2\pi\text{ sq}.\text{units}$
  3. $16^2\pi\text{ sq}.\text{units}$
  4. $25\pi\text{ sq}.\text{units}$
Let $b$ be a nonzero real number. Suppose $f: R \rightarrow R$ is a differentiable function such that $(0)=1$.

If the derivative $f^{\prime}$ of $f$ satisfies the equation $f ^{\prime}( x )=\frac{ f ( x )}{ b ^2+ x ^2}$ for all $x \in R$, then which of the following statements is/are TRUE?

$(A)$ If $b>0$, then $f$ is an increasing function

$(B)$ If $b<0$, then $f$ is a decreasing function

$(C)$ $(x)(-x)=1$ for all $x \in R$

$(D)$ $(x)-f(-x)=0$ for all $x \in R$

Find the general solution of: $\frac{\text{dy}}{\text{dx}}=\text{y}\sin\text{x:}$
  1. y + log sin x + c = 0
  2. log y - cos x - c = 0
  3. log y + cos x - c = 0
  4. None of the above
The value of $\tan \left( {{{\tan }^{ - 1}}\frac{1}{2} - {{\tan }^{ - 1}}\frac{1}{3}} \right)$ is
Area lying between the curves $y^2=4 x$ and $y=2 x$ is _________.
The area bounded by the curve $x=3 y^2-9$ and the line $x=0, y=0$ and $y=1$ is