Thread: Degenerated Conic

If the equation of the curve is



and this curve is such a conic that the focus lies on the directrix.

Can anybody describe the possible situations i.e what happens if is or to 0(zero)

Or

Can anybody provide a link where such a situation has been described.

Thanks in advance.

Originally Posted by pankaj

If the equation of the curve is



and this curve is such a conic that the focus lies on the directrix.

Can anybody describe the possible situations i.e what happens if is or to 0(zero)

: degenerate hyperbola = two straight lines, e.g. .
: degenerate parabola = single straight line, e.g. .
: degenerate ellipse = single point or nothing at all, e.g. or .

Originally Posted by Opalg

: degenerate hyperbola = two straight lines, e.g. .
: degenerate parabola = single straight line, e.g. .
: degenerate ellipse = single point or nothing at all, e.g. or .

Is their proof available