Download App

DETERMINANTS — MATHS STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 ScienceMATHSDETERMINANTS1 Mark
Question
If $\left|\begin{array}{lll}<\text{br}> &1 &\text{amp; } 0 &\text{amp; } 0\\ <\text{br}>&2 &\text{amp; } 3 &\text{amp; } 4\\ <\text{br}>&5 &\text{amp; } -6 &\text{amp; x}<\text{br}> \end{array}\right|=45$ then $\text{x}=$
  1. 4
  2. 7
  3. -5
  4. -7
✓

Answer

  1. 7
Solution:
Given, $\left|\begin{array}{lll}<\text{br}> &1 &\text{amp; } 0 &\text{amp; } 0\\ <\text{br}>&2 &\text{amp; } 3 &\text{amp; } 4\\ <\text{br}>&5 &\text{amp; } -6 &\text{amp; x}<\text{br}> \end{array}\right|=45$
By operation of matrix (5),
$1(3\text{x}+24)=45$
$3\text{x}=21$
$\Rightarrow \text{x}=7$

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

Explore more

More "M.C.Q (1 Marks)" from DETERMINANTS→DETERMINANTS — all question types→MATHS STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

If the position vectors of the vertices of any triangle are $\vec{a}, \vec{b}, \vec{c}$, then the position vector of the centroid of the triangle is :
→
Choose the correct answer in Exercise:
$\int\text{e}^\text{x}\sec\text{x}(1+\tan\text{x})\text{dx}$ equals
  1. $\text{e}^\text{x}\cos\text{x}+\text{C}$
  2. $\text{e}^\text{x}\sec\text{x}+\text{C}$
  3. $\text{e}^\text{x}\sin\text{x}+\text{C}$
  4. $\text{e}^\text{x}\tan\text{x}+\text{C}$
→
The angle which the line $\frac{x}{1}=\frac{y}{-1}=\frac{z}{0}$ makes with the positive direction of $Y$-axis is :
→
Choose the correct answer from the given four options.If $\vec{\text{a}},\vec{\text{b}},\vec{\text{c}}$ are three vectors such that $\vec{\text{a}}+\vec{\text{b}}+\vec{\text{c}}=\vec{0}$ and $|\vec{\text{a}}|=2,|\vec{\text{b}}|=3$ and $|\vec{\text{c}}|=5,$ then the value of $\vec{\text{a}}\cdot\vec{\text{b}}+\vec{\text{b}}\cdot\vec{\text{c}}+\vec{\text{c}}\cdot\vec{\text{a}}$ is:
  1. 0.
  2. 1.
  3. -19.
  4. 38.
→
Two vectors each of magnitudes $1$ unit are inclined at $60^\circ$ to each other. The difference of the vectors has a magnitude $........$?
→
The value of $\sin(2\tan^{-1}(0.75))$ is equal to:
  1. 0.75
  2. 1.5
  3. 0.96
  4. $\sin1.5$
→
$\lim\limits_{\text{n}\rightarrow\infty}\Big\{\frac{1}{2\text{n}+1}+\frac{1}{2\text{n}+2}+\ .....+\frac{1}{2\text{n}+\text{n}}\Big\}$ is equal to:
  1. $\ln\Big(\frac{1}{3}\Big)$
  2. $\ln\Big(\frac{2}{3}\Big)$
  3. $\ln\Big(\frac{3}{2}\Big)$
  4. $\ln\Big(\frac{4}{3}\Big)$
→
The objective function of LPP defined over the convex set attains its optimum value at.
→
Maximize Z = 7x + 11y, subject to $3\text{x}+5\text{y}\leq26,5\text{x}+3\text{y}\leq30,\text{x}\geq0,\text{y}\geq0.$
→
The function $f : R \rightarrow R, f(x) = x^2$ is$:$
→