A parabola is the graph of a quadratic relation which is U-shaped and symmetrical; the U opens either upward or downward and the minimum or maximum point is call the vertex.
Do you see how the dolphin’s head is bending slightly and ready to curve its body to hit the water? The vertex is at the part where the dolphin’s head is bending slightly (red dot is the vertex). The vertex of a parabola is the point which the graph intercepts the axis of symmetry (the point where the parabola starts to bend). An equation that would represent the vertex of a parabola would be y=a(x-h)^+k. in this case h and k would represent the vertex (h represents the x-axis and h represents the y-axis). for example y=a(x-4)+2 the vertex of this equation is (4,2). the reason why the x-axis is 4 and not -4 is because when you look in the bracket what ever the sign is you reverse it. The vertex of the parabola tells how the bending occurs when x=4 and y=2.
