JEE Main2007MathematicsApplication of DerivativesActual
The normal to a curve at P(x, y) meets the x -axis at G . If the distance of G from the origin is twice the abscissa of P , then the curve is a
Options
- Aellipse
- Bparabola
- Ccircle
- Dpair of straight lines
Correct answer
A. ellipse
Step-by-step solution
Equation of normal is Y-y=- d x d y (X-x) aligned & G (x+y d y d x , 0 ) & |x+y d y d x |=|2 x| & y d y d x =x or y d y d x =-3 x & y d y=x d x or y d y=-3 x d x & y^2 2 = x^2 2 +c or y^2 2 =- 3 x^2 2 +c & x^2-y^2=-2 c or 3 x^2+y^2=2 c. aligned