MCQ
Let $A =$$\left[ {\begin{array}{*{20}{c}}1&2&3\\2&0&5\\0&2&1\end{array}} \right]$ and $b =$$\left[ {\begin{array}{*{20}{r}}0\\{ - 3}\\1\end{array}} \right]$ . Which of the following is true?
  • $Ax = b$ has a unique solution.
  • B
    $Ax = b$ has exactly three solutions.
  • C
    $Ax = b$ has infinitely many solutions.
  • D
    $Ax = b$ is inconsistent.

Answer

Correct option: A.
$Ax = b$ has a unique solution.
a
$|A| = 1(0 - 10) - 2(2 - 6)$ $= - 10 + 8 = - 2$

==> $| A | \ne 0$

==>unique solution

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

What is the value of $ \cos (2 \cos^{-1} 0.8)\cos(2\cos−10.8)?$
  1. 0.81
  2. 0.56
  3. 0.48
  4. 0.28
A spherical iron ball of $10 \;\mathrm{cm}$ radius is coated with a layer of ice of uniform thickness the melts at a rate of $50\; \mathrm{cm}^{3} / \mathrm{min}$. When the thickness of ice is $5 \;\mathrm{cm},$ then the rate (in $\mathrm{cm} / \mathrm{min.}$ ) at which of the thickness of ice decreases, is
If $f:\left\{ {1,2,3,4} \right\} \to \left\{ {1,2,3,4} \right\}$ and $y=f(x)$ be a function such that $\left| {f\left( \alpha  \right) - \alpha } \right| \leqslant 1$,for $\alpha  \in \left\{ {1,2,3,4} \right\}$ then total number of such functions are
$\int_{}^{} {\frac{1}{{\log a}}({a^x}\cos {a^x})dx = } $
A random variable $X$ has the probability distribution  ....For the events $E = \{ X$is prime number $\}$ and $F = \{ X < 4\} $, the probability of $P(E \cup F)$ is
$X$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$
$P(X)$ $0.15$ $0.23$ $0.12$ $0.10$ $0.20$ $0.08$ $0.07$ $0.05$
If the function $f(x) = \left[ {\frac{{{{(x - 2)}^3}}}{a}} \right]\,\sin \,(x - 2)\, + a\cos (x - 2)\,$ is continious in $[4, 6],$ then the value of $a$ is $([.]$ denotes the greatest integer function)
If $\tan ^{-1}\left(\frac{3}{4}\right)=\theta$ then value of $\sin \theta$ is :
Let $f$ be a real-valued function defined on the interval $(0, \infty)$ by $f(x)=\ln x+\int_0^x \sqrt{1+\sin t} d t$. Then which of the following statement(s) is (are) true?

$(A)$ $f^{\prime \prime}(x)$ exists for all $x \in(0, \infty)$

$(B)$ $f^{\prime}(x)$ exists for all $x \in(0, \infty)$ and $f^{\prime}$ is continuous on $(0, \infty)$, but not differentiable on $(0, \infty)$

$(C)$ there exists $\alpha>1$ such that $\left|f^{\prime}(x)\right|<|f(x)|$ for all $x \in(\alpha, \infty)$

$(D)$ there exists $\beta>0$ such that $|f(x)|+\left|f^{\prime}(x)\right| \leq \beta$ for all $x \in(0, \infty)$

The values of $x $ in the following determinant equation, $\left| {\,\begin{array}{*{20}{c}}{a + x}&{a - x}&{a - x}\\{a - x}&{a + x}&{a - x}\\{a - x}&{a - x}&{a + x}\end{array}\,} \right| = 0$ are
The value of integral $\int\limits_{\frac{\pi }{4}}^{\frac{{3\pi }}{4}} {\frac{x}{{1 + \sin x}}} dx$ is