MCQ
Let $a, \lambda, \mu \in \mathbb{R}$. Consider the system of linear equations

$a x+2 y=\lambda$

$3 x-2 y=\mu$Which of the following statement($s$) is(are) correct?

($A$) If $a=-3$, then the system has infinitely many solutions for all values of $\lambda$ and $\mu$

($B$) If $a \neq-3$, then the system has a unique solution for all values of $\lambda$ and $\mu$

($C$) If $\lambda+\mu=0$, then the system has infinitely many solutions for $a=-3$

($D$) If $\lambda+\mu \neq 0$, then the system has no solution for $a=-3$

  • A
    $A,C$
  • B
    $B,C$
  • $B,C,D$
  • D
    $B,C,A$

Answer

Correct option: C.
$B,C,D$
c
$\alpha x+2 y=\lambda$

$3 x-2 y=\mu$

$\Delta=\left|\begin{array}{ll}\alpha & 2 \\ 3 & -2\end{array}\right|=-2 \alpha-6$

$\Delta=0, \therefore, \alpha=-3$

$\Delta_1=\left|\begin{array}{ll}\lambda & 2 \\ \mu & -2\end{array}\right|=-2 \lambda-2 \mu=-2(\lambda+\mu)$

$\Delta_2=\left|\begin{array}{ll}-3 & \lambda \\ 3 & \mu\end{array}\right|=-3 \mu-3 \lambda=-3(\lambda-\mu)$

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

The function $f(x) = \left\{ {\begin{array}{*{20}{c}}{{e^{2x}} - 1}&,&{x \le 0}\\{ax + \frac{{b{x^2}}}{2} - 1}&,&{x > 0}\end{array}} \right.$ is continuous and differentiable for
If function $f(x)=\left\{\begin{array}{cl}\frac{e^{3 x}-e^{-5 x}}{x} & , \text { if } x \neq 0 \\ k & , \text { if } x=0\end{array}\right.$ is continuous then value of $k$ :
The value of $\int \limits_{0}^{\pi} \frac{e^{\cos x} \sin x}{\left(1+\cos ^{2} x\right)\left(e^{\cos x}+e^{-\cos x}\right)} d x$ is equal to
Let × be a binary operation on Q, defined by $\text{a}\times\text{b}=\frac{3\text{ab}}{5}$ is:
  1. Commutative.
  2. Associative.
  3. Both (a) and (b).
  4. None of these.
Let $f : [0,1]\,\to R$ be such that $f\,(xy) = f\,(x)\,f\,(y)$ for all $x,y\,\in [0,1],$ and $f \,(0)\,\ne 0.$ If $y=y\,(x)$ satisfies the differential equation,$\frac{{dy}}{{dx}} = f(x)$ with $y(0) = 1,$ then $y\left( {\frac{1}{4}} \right) + y\left( {\frac{3}{4}} \right)$ is equal to
The mean and variance of a random variable $X$ having a binomial distribution are $4$ and $2$ respectively, then $P(X = 1)$ is
Let $X$ be a random variable such that the probability function of a distribution is given by $P(X=$ 0) $=\frac{1}{2}, \mathrm{P}(\mathrm{X}=\mathrm{j})=\frac{1}{3^{j}}(\mathrm{j}=1,2,3, \ldots, \infty)$. Then the mean of the distribution and $\mathrm{P}(\mathrm{X}$ is positive and even) respectively are:
If $f(x) = mx + c,f(0) = f'(0) = 1$ then $f(2) = $
If $\hat{a}, \hat{b}, \hat{c}$ are unit vectors, then least value of $\left | \hat{a}+\hat{b} \right |^2+\left | \hat{b}+\hat{c} \right |^2+\left | \hat{c}+\hat{a} \right |^2$ will be-
${\cos ^{ - 1}}\frac{1}{2} + 2{\sin ^{ - 1}}\frac{1}{2}$ is equal to