Parabola: y = ax 2+bx+c that is, y equals the square of ax+bx+C.
A>0, opening up, a
That is, y is equal to a times the square of (x+h)+k, -h is the x of vertex coordinates, and y of vertex coordinates is generally used to find the maximum and minimum values. The standard equation of the object line is y 2 = 2px.
It means that the focus of parabola is on the positive semi-axis of X, the focal coordinate is (p/20), and the directrix equation is x=-p/2. Because the focus of parabola can be on any semi-axis, * * has standard equations Y 2 = 2px, y 2 =-2px, x 2 = 2py, x 2 =-2py (p&g t; 0)。