The angle between the vectors i - j + k and i + 2j + k is - Vidyadip

MCQ

The angle between the vectors $i - j + k$ and $i + 2j + k$ is

A
${\cos ^{ - 1}}\left( {\frac{1}{{\sqrt {15} }}} \right)$
B
${\cos ^{ - 1}}\left( {\frac{4}{{\sqrt {15} }}} \right)$
C
${\cos ^{ - 1}}\left( {\frac{4}{{15}}} \right)$
✓
$\frac{\pi }{2}$

✓

Answer

Correct option: D.

$\frac{\pi }{2}$

d
(d) $(i - j + k)\,.\,(i + 2j + k) = \sqrt 3 \sqrt 6 \cos \theta $

$ \Rightarrow \cos \theta = \frac{0}{{\sqrt 3 \sqrt 6 }} \Rightarrow \theta = \frac{\pi }{2}.$

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 STD 12 - 10. vector algebra→STD 12 - 10. vector algebra — all question types→Mathematics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

The solution of the inequallity $(cot^{-1}x)^2 -5cot^{-1}x + 6 > 0$ is :-

If A is a square matrix of order 3 and |A| = 5, then the value of |2A′| is:

If $f(x) = \left\{ {\begin{array}{*{20}{c}}{4x + 3\,,}&{{\rm{if}}}&{1 \le x \le 2}\\{3x + 5\,,}&{{\rm{if}}}&{2 < x \le 4}\end{array}} \right.$ then $\int_1^4 {\,f(x)} \,dx = $

The value of the determinant $\left| {\,\begin{array}{*{20}{c}}4&{ - 6}&1\\{ - 1}&{ - 1}&1\\{ - 4}&{11}&{ - 1\,}\end{array}} \right|$is

In a sphere the rate of change of surface area is:

The volume of a sphere is increasing at $3\ cm^3/ \sec$. The rate at which the radius increases when radius is $2\ cm$, is :

Choose the correct answer from the given four options:
Area of the region bounded by the curve $\text{y}\cos\text{x}$ between x = 0 and $\text{x}=\pi$ is:

Choose the correct answer in Exercise:
The value of $\int^{1}_{0}\tan^{-1}\bigg(\frac{2\text{x}-1}{1+\text{x}-\text{x}^{2}}\bigg)\text{dx}$ is

The distance of the plane $2x - 3y + 6z + 7 = 0$ from the point $(2, -3, -1)$ is:

If the shortest distance between the lines $\vec{r}_{1}=\alpha \hat{i}+2 \hat{j}+2 \hat{k}+\lambda(\hat{i}-2 \hat{j}+2 \hat{k}), \lambda \in R, \alpha>0$ and $\vec{r}_{2}=-4 \hat{i}-\hat{k}+\mu(3 \hat{i}-2 \hat{j}-2 \hat{k}), \mu \in R$ is $9$, then $\alpha$ is equal to $.....$