Subjective Type

Write two different vectors having same direction

Solution

Consider $$\vec {p}=\left (\hat {i}+\hat {j}+\hat {k}\right )$$ and $$\vec {q}=\left (2\hat {i}+2\hat j+2\hat k\right )$$
The directions cosines of $$\vec {p}$$ are given by,
$$l=\dfrac {1}{\sqrt {1^2+1^2+1^2}}=\dfrac {1}{\sqrt {3}}, m=\dfrac {1}{\sqrt {1^2+1^2+1^2}}=\dfrac {1}{\sqrt {3}}$$, and $$n=\dfrac {1}{\sqrt {1^2+1^2+1^2}}=\dfrac {1}{\sqrt {3}}$$.
The direction cosines of $$\vec {q}$$ are given by
$$l=\dfrac {2}{\sqrt {2^2+2^2+2^2}}=\dfrac {2}{2\sqrt 3}=\dfrac {1}{\sqrt {3}}, m=\dfrac {2}{\sqrt {2^2+2^2+2^2}}=\dfrac {2}{2\sqrt 3}=\dfrac {1}{\sqrt {3}}$$, and $$n=\dfrac {2}{\sqrt {2^2+2^2+2^2}}=\dfrac {2}{2\sqrt 3}=\dfrac {1}{\sqrt {3}}$$.
The direction cosines of $$\vec {p}$$ and $$\vec {q}$$ are the same. Hence, the two vectors have the same direction.


SIMILAR QUESTIONS

Vector Algebra

If $$\overrightarrow{a}$$ and $$\overrightarrow{b}$$ two collinear vectors then which of the following are incorrect

Vector Algebra

Show that the lines $$\overleftrightarrow {PQ}$$ are $$\overleftrightarrow {RQ}$$ parallel where P,Q,R,S are the points $$(2,3,4),(4,7,8),(-1,-2,1)$$ and $$(1,2,5)$$ respectively.

Vector Algebra

Show that the vectors $$ 2\hat{i}-3\hat{j}+4\hat{k}$$ and $$ -4\hat{i}+6\hat{j}-8\hat{k}$$ are collinear.

Vector Algebra

Answer the following as true or false. (i) a⃗ and −a⃗ are collinear (ii) Two collinear vectors are always equal in magnitude. (iii) Two vectors having same magnitude are collinear. (iv) Two collinear vectors having the same magnitude are equal.

Vector Algebra

Write two different vectors having same direction

Contact Details