Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
Home  >>  CBSE XII  >>  Math  >>  Model Papers
0 votes

If \( |\overrightarrow a|=\sqrt 3, |\overrightarrow b|=2\) and the angle between \( \overrightarrow a \: and \: \overrightarrow b\) is \( 60^{\circ}\), find \( \overrightarrow a.\overrightarrow b\)

Can you answer this question?

1 Answer

0 votes
  • $\overrightarrow a.\overrightarrow b=\mid a\mid \mid b\mid\cos\theta$
Step 1:
Given :
$\mid \overrightarrow a\mid=3,\mid \overrightarrow b\mid=2$
$\theta =60^{\circ}$
$\therefore \overrightarrow a.\overrightarrow b=\mid \overrightarrow a\mid.\mid \overrightarrow b\mid \cos\theta$
Substituting the values we get,
$\overrightarrow a.\overrightarrow b=3\times 2\cos 60^{\circ}$
Step 2:
But $\cos 60^{\circ}=\large\frac{1}{2}$
$\therefore \overrightarrow a.\overrightarrow b=3\times 2\times \large\frac{1}{2}$
$\overrightarrow a.\overrightarrow b=3$units.
answered Sep 24, 2013 by sreemathi.v

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App