Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • Please Solve R.D.Sharma class 12 Chapter 25 Scalar Triple Product Exercise 25 .1 Question 2 Sub Question 2 Maths textbook Solution.

Please Solve R.D.Sharma class 12 Chapter 25 Scalar Triple Product  Exercise 25 .1 Question 2 Sub Question 2 Maths textbook Solution.

Answers (1)

Answer :- \left [ \vec{a}\:\: \vec{b}\:\: \vec{c} \right ]=12

Hint :- Use cross product & dot product

Given: \vec{a}=\hat{i}-2\hat{j}+3\hat{k}

\begin{aligned} &\vec{b}=2 \hat{\imath}+\hat{\jmath}-\hat{k} \\ &\vec{c}=\hat{\jmath}+\hat{k} \\ \end{aligned}

       \begin{aligned} &\text { For, }[\vec{a} \vec{b} \vec{c}]=(\vec{a} \times \vec{b}) \cdot \vec{c} \\ \end{aligned}

\begin{aligned} &\vec{a} \times \vec{b}=\left|\begin{array}{ccc} \hat{\imath} & \hat{\jmath} & \hat{k} \\ 1 & -2 & 3 \\ 2 & 1 & -1 \end{array}\right| \\ \end{aligned}

            \begin{aligned} &=\hat{l}(2-3)-\hat{\jmath}(-1-6)+\hat{k}(1+4) \\ &=-\hat{\imath}+7 \hat{j}+5 \hat{k} \\ \end{aligned}

  \begin{aligned} &(\vec{a} \times \vec{b}) \cdot \vec{c}=(-\hat{\imath}+7 \hat{\jmath}+5 \hat{k}) \cdot(\hat{\jmath}+\hat{k}) \\ &=7+5 \\ &=12 \end{aligned}

\therefore \left [ \vec{a}\:\: \vec{b}\:\: \vec{c} \right ]=12

Posted by

infoexpert21

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 Central Sector Scheme of Scholarship 2025 applications open on scholarships.gov.in
anam-khan

CBSE Board 2025: Class 10th, 12th supplementary date sheet out; exams from July 15
anam-khan

CBSE issues final reminder to schools for supplementary exam LOC submission; submit by today without late fee

Latest Question