MCQ
If $a,\,b,\,c$ are non-coplanar vectors and $d = \lambda a + \mu \,b + \nu c,$ then $\lambda $ is equal to
  • A
    $\frac{{[d\,b\,c]}}{{[b\,a\,c]}}$
  • $\frac{{[b\,c\,d]}}{{[b\,c\,a]}}$
  • C
    $\frac{{[b\,d\,c]}}{{[a\,b\,c]}}$
  • D
    $\frac{{[c\,b\,d\,]}}{{[a\,b\,c]}}$

Answer

Correct option: B.
$\frac{{[b\,c\,d]}}{{[b\,c\,a]}}$
b
(b) Since  $d=\lambda a+\mu b+\nu c$

$\therefore d.(b\times c)=\lambda \,a.(b\times c)+\mu \,b.(b\times c)+\mu \,c.(b\times c)$

$=\lambda \left[ abc \right]$

$⇒\lambda =\frac{[\,dbc]}{[abc]}$  $=\frac{[bcd]}{[bca]}$

 

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

$\int {\frac{{x\,\,dx}}{{{x^2} + 4x + 5}} = } $
The function $\text{f}(\text{x})=2\log(\text{x}-2)-\text{x}^2+4\text{x}+1$ increases on the interval:
  1. (1, 2)
  2. (2, 3)
  3. (1, 3)
  4. (2, 4)
Which pair $(s)$ of function $(s)$ is/are equal ?

where $\{x\}$ and $[x]$ denotes the fractional part $\&$ integral part functions.

The points $O,A,B,C,D$ are such that $\overrightarrow {OA}  = \vec a,\,\overrightarrow {OB}  = \vec b,\,$ $\overrightarrow {OC}  = \,2\vec a + 3\vec b\,$ and$ \,\overrightarrow {OD}  = \,\vec a - 2\vec b.\,\,$ If $ \,\left| {\vec a} \right|\, = 3\left| {\vec b,} \right|$ then the angle between $\overrightarrow {BD} $ and $\overrightarrow {AC} $ is
The minimum value of Z = 3x + 5y subjected to constraints $\text{x}+3\text{y}\geq3,\text{x}+\text{y}\geq2,\text{x},\text{y}\geq0$ is:
  1. 5
  2. 7
  3. 10
  4. 11
The radius of a circular plate is increasing at the rate of 0.01cm/sec. The rate of increase of its area when the radius is 12cm, is:

  1. $144\pi\text{cm}^{2}/\text{sec}.$

  2. $2.4\pi\text{cm}^{2}/\text{sec}.$

  3. $0.24\pi\text{cm}^{2}/\text{sec}.$ 

  4. $0.024\pi\text{cm}^{2}/\text{sec}.$   

If A and B are two independent events with $\text{P(A)}=\frac{3}{5}$ and $\text{P(B)}=\frac{4}{9},$ then $\text{P}(\overline{\text{A}}\cap\overline{\text{B}})$ equals,
  1. $\frac{4}{15}$
  2. $\frac{8}{45}$
  3. $\frac{1}{3}$
  4. $\frac{2}{9}$
A point from a vector starts is called and where it ends is called its:
  1. Terminal point, endpoint.
  2. Initial point, terminal point
  3. Origin, endpoint
  4. Initial point, endpoint
If $A$ and $B$ are two invertible square matrices of the same order such that $(A + B)(A -B) = A^2-B^2$, then $(A^2BA^{-1}B^{-1})^3$ is equal to-
The binary operation * defined on N by a * b = a + b + ab for all a, b ∈ N is:
  1. Commutative only.
  2. Associative only.
  3. Commutative and associative both.
  4. None of these.