Most chordates are vertebrates. Invertebrate chordates, which belong to two of the subphyla of chordatesâCephalochordata and Urochordata, also have a dorsal tubular nerve cord, a notochord, pharyngeal pouches, a postanal tail, and, possibly, an ancestral thyroid gland.They ha ve no backbone, however.ost chordates are vertebrates. Invertebrate chordates, which belong to two of the subphyla of chordatesâCephalochordata and Urochordata, also have a dorsal tubular nerve cord, a notochord, pharyngeal pouches, a postanal tail, and, possibly, an ancestral thyroid gland. They ha ve no backbone, however.
Quadratic Equation. An equation where the highest exponent of the variable (usually x) is a square (2). It is usually written ax2+bx+c = 0 Example: 2x2+5x-3 = 0. See: Exponent. Quadratic Equations.
Quadratic functions are functions in which the 2nd power, or square, is the highest to which the unknown quantity or variable is raised.. The function y=x2 or f(x) = x2 is a quadratic function, and is the parent graph for all other quadratic functions. The shortcut to graphing the function f(x) = x2 is to start at the point (0, 0) (the origin) and mark the point, called the vertex. Note that the point (0, 0) is the vertex of the parent function only. In calculus, this point is called a critical point, and some pre-calculus teachers also use that terminology.