Ask Questions, Get Answers

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

Equation of the parabola if its vertex and focus are $(-2,3)$ and $(1,-1)$ respectively is

$\begin{array}{1 1}(A)\;16x^2+24xy+9y^2-308x+394y-1799=0 \\(B)\;16x^2+24xy+9y^2-308x-394y-1799=0 \\(C)\;16x^2-24xy+9y^2-308x+394y-1799=0 \\(D)\;none\;of\;these \end{array}$

Can you answer this question?

1 Answer

0 votes
Distance between focus and vertex.
$\qquad= \sqrt {(1+2)^2+(1-3)^2}=5$
Let point of intersection of direction and axis of parabola be $(x_1,y_1)$
then $\large\frac{x_1+1}{2}$$=-2$
=> $x_1=-5$
and $\large\frac{y_1-1}{2}$$=3$
=> $y_1=7$
Equation of direction is $y-7 =\large\frac{3}{4}$$(x+5)$
equation of the required parabola is $\bigg( \large\frac{3x-4y+43}{5}\bigg)^2$$=(x-1)^2+(y-1)^2$
$16x^2+24xy+9y^2-308x+394y-1799=0 $
Hence A is the correct answer.
answered Apr 9, 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