拋物線反曲線

x

=

at^2

y

=

2at

(x_0,y_0)

k

x

=

x_0+(k(at^2-x_0))/((at^2+x_0)^2+(2at-y_0)^2)

y

=

y_0+(k(2at-y_0))/((at^2+x_0)^2+(2at-y_0)^2).

(x_0,y_0)=(0,0)

x

=

k/(a(4+t^2))

y

=

(2k)/(at(4+t^2)).

(x_0,y_0)=(a,0)

x

=

a+(k(t^2-1))/(a(1+t^2)^2)

y

=

(2kt)/(a(1+t^2)^2).