1 Derivan Oil Based Patina has now been discontinued and no longer in production. 2  Derivan CanvasJack, a unique artist quality range of stretched canvases and tensioning system. 3  Our Face & Body range has just being expanded with new Face Paint Markers and Wipes. Add even more fun to your face painting. 2  Derivan continues to expand its range of artists materials with the new, professional artist grade, Derivan Watercolours range. 3  Three new colours extends Derivan Block Ink range. 4  Just released, MM32 Light Modelling Paste a NEW modelling compound added to Matisse Mediums range.
You can think of the formula for finding the vertex of a quadratic function as being (x, y) = [(-b/2a), f(-b/2a)] . This just means that to get the y value, you have to find the x value based on the formula and then plug it back into the equation. Here's how you do it: 1  y = x 2 + 9x + 18.
Specifically, we can use y = 3x2 + 6x + 1 as an example. Notice that the point at (-1,-2) is the lowest point on the graph. This is what we call the vertex. We can also find the coordinates of the vertex from the equation itself, using this formula: x = -b/2a. In this case, x = -6/2(3) = -6/6 = -1.