Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • Please solve RD Sharma Class 12 Chapter 24 Vector or Cross Product Exercise Very Short Answer Question, question 7 Maths textbook solution.

Please solve RD Sharma Class 12 Chapter 24 Vector or Cross Product Exercise Very Short Answer Question, question 7 Maths textbook solution.

Answers (1)

ANSWER:

\left | a \right |^2\left | b \right |^2

HINT:

 Just drive the formulas for dot product and cross product and add them.

GIVEN:

SOLUTION:

\begin{aligned} &|\vec{a} \times \vec{b}|=|\vec{a}| \cdot|\vec{b}| \sin \theta \cdot \widehat{n} \\ &|\vec{a} \times \vec{b}|=|\vec{a}| \cdot|\vec{b}| \sin \theta .1 \quad(\because \widehat{n}=1, \text { as it is unit vector }) \\ &|\vec{a} \times \vec{b}|^{2}=|\vec{a}|^{2} \cdot|\vec{b}|^{2} \operatorname{\sin}^{2} \theta \ldots \ldots \ldots \ldots \ldots(1) \end{aligned}

\begin{aligned} &|\vec{a} \vec{b}|=|\vec{a}| \cdot|\vec{b}| \cos \theta \\ &|\vec{a} \vec{b}|^{2}=|\vec{a}|^{2} \cdot|\vec{b}|^{2} \operatorname{\cos}^{2} \theta . ............................(2)\\ &\text { Adding }(1) \&(2) \end{aligned}

\begin{aligned} |\vec{a} \times \vec{b}|^{2}+|\vec{a} \vec{b}|^{2} &=|a|^{2}|b|^{2}\left(\sin ^{2} \theta+\operatorname{Cos}^{2} \theta\right) \\ &=|a|^{2}|b|^{2}(1) \\ &=|a|^{2}|b|^{2} \end{aligned}

Posted by

infoexpert24

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 Class 12 Computer Science Exam Analysis 2025: Paper 'moderate', but 'tougher' than last three years
anam-khan

CBSE Class 12 Accountancy Exam Analysis 2025: Paper ‘moderate', includes application-based questions
anam-khan

CBSE mulls allowing non-programmable, basic calculators for class 12 Accountancy exam

Latest Question