MCQ
If the vectors $2i - j + k,\,\,i + 2j - 3k$ and $3i + \lambda j + 5k$ be coplanar, then $\lambda = $
  • A
    $-1$
  • B
    $-2$
  • C
    $-3$
  • $-4$

Answer

Correct option: D.
$-4$
d
(d) If the given vectors are coplanar, then their scalar triple product is zero.

$\left| {\begin{array}{*{20}{c}}2&{ - 1}&1\\1&2&{ - 3}\\3&\lambda &5\end{array}} \right| = 0 \Rightarrow \lambda = - 4.$

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 rank of the matrix, $A = \left[ {\begin{array}{*{20}{c}}2&3&1&4\\0&1&2&{ - 1}\\0&{ - 2}&{ - 4}&2\end{array}} \right]$ is
$\big(\vec{\text{a}}+\vec{\text{b}}\big).\big(\vec{\text{b}}+\vec{\text{c}}\big)\times\big(\vec{\text{a}}+\vec{\text{b}}+\vec{\text{c}}\big)=$
  1. $0$
  2. $-\big[\vec{\text{a}}\vec{\text{b}}\vec{\text{c}}\big]$
  3. $2\big[\vec{\text{a}}\vec{\text{b}}\vec{\text{c}}\big]$
  4. $\big[\vec{\text{a}}\vec{\text{b}}\vec{\text{c}}\big]$
The number of arbitary constant in particular solution of fourth order differential equation is ___________ .
The differential equation of all circles which passes through the origin and whose centre lies on $y$-axis, is
If one ball is drawn ar random from each of three boxes containing 3 white and 1 black, 2 white and 2 black, 1 white and 3 black balls, then the probability that 2 white and 1 black balls will be drawn is.
  1. $\frac{13}{32}$
  2. $\frac{1}{4}$
  3. $\frac{1}{32}$
  4. $\frac{3}{16}$
The projection of vector $2i + 3j - 2k$ on the vector $i + 2j + 3k$ will be
$\int_{}^{} {5\sin xdx = } $
Let a function $f : R \rightarrow  R$ is defined such that $3f(2x^2 -3x + 5) + 2f(3x^2 -2x + 4) = x^2 -7x + 9\ \ \  \forall  x \in R$, then the value of $f(5)$ is-
If the events $A$ and $B$ are mutually exclusive events such that $P\left( A \right) = \frac{{3x + 1}}{3}$ and $P\left( B \right) = \frac{{1 - x}}{4}$, then the set of possible values of $x$ lies in the interval
If every row of a matrix A contains p elements and its column contains q elements, then the order of A is:
  1. p × p
  2. q × q
  3. p × q
  4. q × p