Ask Questions, Get Answers

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

If the tangent at the point P on the circle $x^2+y^2+6x=2$ meets a straight line $5x-2y+6=0$ at a point Q on the y-axis , then the length of $PQ$ is

$\begin{array}{1 1}(A)\;4\\(B)\;2 \sqrt 5\\(C)\;5 \\(D)\;3 \sqrt 5 \end{array}$

Can you answer this question?

1 Answer

0 votes
Line $5x-2y+6=0$ is intersected by tangent P to circle $x^2+y^2+6x+6y-2=0$ on y-axis at $Q(0,3)$
In other words tangent passes through $(0,3)$
$PQ$= length of tangent to circle from $(0,3)$
$\qquad= \sqrt {0+9+0+18-2}$
$\qquad= \sqrt {25}$
$\qquad= 5$
Hence C is the correct answer.
answered Apr 8, 2014 by meena.p

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