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 maths class 12 chapter 27 Straight Line in Space exercise Multiple choice question 2

Provide solution for RD Sharma maths class 12 chapter 27 Straight Line in Space exercise Multiple choice question 2

Answers (1)

best_answer

Answer: Correct answer is A.

Hint: Use vector cross product.

 

Given:: \frac{x}{1}=\frac{y}{2}=\frac{z}{3} \text { and } \frac{x-1}{-2}=\frac{y-2}{-4}=\frac{z-3}{-6}

 

Solution: The equation of the given lines are

\begin{aligned} &\frac{x}{1}=\frac{y}{2}=\frac{z}{3} \rightarrow(1) \\\\ &\text { and } \frac{x-1}{-2}=\frac{y-2}{-4}=\frac{z-3}{-6} \\\\ &\Rightarrow \frac{x-1}{1}=\frac{y-2}{2}=\frac{z-3}{3} \rightarrow(2) \end{aligned}
Thus the two lines are parallel to the vector \vec{b}=\hat{\imath}+2 \hat{\jmath}+3 \hat{k} and pass through the points (0,0,0)and (1,2,3).

Now,

\begin{aligned} &\left(\overrightarrow{a_{1}}-\overrightarrow{a_{2}}\right) \times \vec{b} \\\\ &=(\hat{\imath}+2 \hat{\jmath}+3 \hat{k}) \times(\hat{\imath}+2 \hat{\jmath}+3 \hat{k}) \\\\ &=\overrightarrow{0} \\\\ &\Rightarrow(\vec{a} \times \vec{a}=\overrightarrow{0}) \end{aligned}

Since the distance between the two parallel lines is 0, the given lines are coincident.

So, the correct option is (a) coincident.

Posted by

infoexpert26

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 result verification 2024 application out at cbse.gov.in; last date, fees
anam-khan

CBSE results 2024 later for 102 students over fake certificates; board issues show cause notice
anam-khan

What after CBSE Class 12 results 2024? From CUET UG to JEE Advanced, all you need to know

Latest Question