Chord length formula refers to the formula of chord length d obtained by intersection of straight line and conic curve. Conic curves are some curves obtained by cutting a cone flat in mathematics and geometry (strictly speaking, a right conical surface is completely tangent to a plane), such as ellipse, hyperbola, parabola and so on.
Chord length formula:
Parabola y2=2px, and the straight line passing through the focus intersects the parabola.
If the straight line is at two points A(x 1, y 1) and B(x2, y2), the chord length of AB is d=p+x 1+x2 y2=-2px, and the straight line passing through the focus intersects a parabola. (x 1, y 1) and b (x 2, y 2), then the chord length of AB is d = p-x1+x 2.
X2=2py, and if the straight line passing through the focal point intersects the parabola at two points: a ﹙ x 1 ﹚ and B﹙x2,y2﹚, then the chord length of AB is d=p+y 1+y2.
X2=-2py, if the straight line passing through the focal point intersects the parabola at two points: a ﹙ x 1 ﹚ and B﹙x2,y2﹚, then the chord length of AB is d = p-y1+y2.