Ask Questions, Get Answers

Home  >>  JEEMAIN and NEET  >>  Mathematics  >>  Class12  >>  Differential Equations

Find nature of curve not passing through origin for which tangent at any point P. on curve is equal to radius vector of point P.

$(a)\;x^2-y^2=c \\ (b)\;y^2+9x^2+6=c \\ (c)\;x^2+3xy^2-y=c \\ (d)\;x^2+3y^2=c $

1 Answer

Equation of normal at P
=> $ X+mY=x +my$
$PN=\sqrt {m^2y^2+y^2}$
$OP= PN$
$x^2 =m^2y^2$
$\large\frac{dy}{dx}$$=m =\pm \large\frac{x}{y}$
=> $ \int y dy =\pm \int x dy$
$x^2+y^2=c$ (circle)
or $x^2-y^2=c$
Hence a is the correct answer.
answered Feb 7, 2014 by meena.p

Related questions