Show that the magnitude of a vector is equal to the square root of the scalar product of the vector with itself.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) Let $\overrightarrow{A}$ be a vector. The scalar product (dot product) of the vector $\overrightarrow{A}$ with itself is defined as $\overrightarrow{A} \cdot \overrightarrow{A} = |\overrightarrow{A}| |\overrightarrow{A}| \cos \theta$.
Since the angle $\theta$ between a vector and itself is $0^{\circ}$,we have $\cos 0^{\circ} = 1$.
Therefore,$\overrightarrow{A} \cdot \overrightarrow{A} = |\overrightarrow{A}| |\overrightarrow{A}| (1) = |\overrightarrow{A}|^2$.
Taking the square root on both sides,we get $|\overrightarrow{A}| = \sqrt{\overrightarrow{A} \cdot \overrightarrow{A}}$.
Thus,the magnitude of a vector is equal to the square root of the scalar product of the vector with itself.

Explore More

Similar Questions

Explain the geometrical interpretation of the scalar product of two vectors.

The angle between vectors $(\vec{M} \times \vec{N})$ and $(\vec{N} \times \vec{M})$ is ................ (in $^{\circ}$)

If $\vec{A} + \vec{B} + \vec{C} = 0$,then $\vec{A} \times \vec{B}$ is equal to:

Which of the following is the unit vector perpendicular to $\vec{A}$ and $\vec{B}$?

Consider two vectors $\vec{F}_1 = 2\hat{i} + 5\hat{k}$ and $\vec{F}_2 = 3\hat{j} + 4\hat{k}$. The magnitude of the scalar product of these vectors is

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo