Standard form: y=ax^2+bx+c. Examples. Vertex form is obtained by calculating first a delta and next p i q. p = -b/2a, q = -Δ/4a. From vertex form it is easy to read coordinates vertex of the parabola. x_w = p, y_w = q. Factored form is obtained from the standard form by calculating roots. Its shape depend on delta: Δ gt; 0 - y = a(x-x_1)(x-x_2); Δ = 0 - y = a(x-x_1)^2, Δ < 0 - not exist.