Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • Provide Solution for RD Sharma Class 12 Chapter 23 Scalar or Dot Products Exercise Very Short Answer Question 10

Provide Solution for RD Sharma Class 12 Chapter 23 Scalar or Dot Products Exercise Very Short Answer Question 10

Answers (1)

ANSWER: 4

GIVEN:  |\vec{a}|=|\vec{b}|, \theta=60^{\circ} \quad \& \quad \vec{a} \cdot \vec{b}=8

HINTS: use the formula of cosθ

SOLUTION:Let,

  $$ |\vec{a}|=|\vec{b}|=x

We know that

\cos \theta=\frac{\vec{a} \cdot \vec{b}}{|\vec{a}||\vec{b}|}

\begin{aligned} &\Rightarrow \cos 60^{\circ}=\frac{8}{xx x}\qquad\left[\because \theta=60^{\circ}, \vec{a} \cdot \vec{b}=8, \overline{\mid a}|=| \vec{b} \mid=x\right] \\ & \end{aligned}

\Rightarrow \frac{1}{2}=\frac{8}{x^{2}} \qquad\left[\because \cos 60^{\circ}=\frac{1}{2}\right] \\

\Rightarrow x^{2}=16 \\

\Rightarrow x=4 \\

\therefore|\vec{a}|=\vec{|b|}=4

 

Posted by

infoexpert27

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

Similar Questions

Trending Articles/News

anam-khan

CBSE opens portal for uploading internal grades for Class 12 board practical exams 2025
anam-khan

Record 3.25 crore students register for PM Modi's Pariksha Pe Charcha 2025
anam-khan

Over 3 crore students register for PM Modi’s Pariksha Pe Charcha 2025

Latest Question