Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
Home  >>  JEEMAIN and AIPMT  >>  Mathematics  >>  Class11  >>  3-D Geometry
0 votes

The line through the points $(5,1,a)\:\:and\:\:(3,b,1)$ crosses $yz$ plane at the point $(0,\large\frac{17}{2},-\frac{13}{2})$, then $(a,b)=?$

$\begin{array}{1 1}(a)\:\:(8,2)\\ (b)\:\:(2,8) \\ (c)\:\:(4,6) \\ (d)\:\:(6,4) \end{array} $

Can you answer this question?

1 Answer

0 votes
Let $P(5,1,a)\:\:and\:\:Q(3,b,1)$ be the given points.
$\therefore\:$Eqn. of the line $\overline {PQ}$ is $\large\frac{x-3}{2}=\frac{y-b}{1-b}=\frac{z-1}{a-1}$$=\lambda$
This line crosses yz plane at $(0,\large\frac{17}{2},-\frac{13}{2})$
$\Rightarrow\:2\lambda+3=0,\:\:\frac{17}{2}=$$(1-b)\lambda+b$ and $(a-1)\lambda+1=-\large\frac{13}{2}$
$\Rightarrow\:b=4\:\:and\:\:a=6$ $i.e., (a,b)=(6,4)$


answered Dec 27, 2013 by rvidyagovindarajan_1

Related questions

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