Question

A focal chord of a parabola is a chord of the parabola that passes through the focus
a) prove that the x-coordinates of the endpoints of a focal chord of x^2=4py are x=2p(m±√(m^2 +1), where m is the slope of the focal chord.
b) Using part (a), prove the minimum length of a focal chord is the focal width I 4p I

Answer 1

isn't the slope of the focal chord 0 for this equation? m=0?

Answer 2

so it's just a point?

Answer 3

ugh so confused
can you show me a diagram of this or something?

Answer 4

no...