Central angle intersection points and of the legs of the angle with the circle form a diameter, then is a straight angle. (In radians, .) Let be the minor arc of the circle between points and , and let be the radius of the circle. If the central angle is subtended by , then If the central angle is not subtended by the minor arc , then is a reflex angle and If a tangent at and a tangent at intersect at the exterior point , then denoting the center as , the angles (convex) and are supplementary (sum to 180°). A
Angle condition from which we derive the angle condition: for formula_5, are the angles of zeros 1 to "n", and are the angles of poles 1 to "m". The magnitude condition is derived similarly. Angle condition In mathematics, the angle condition is a constraint that is satisfied by the locus of points in the s-plane on which closed-loop poles of a system reside. In combination with the magnitude condition, these two mathematical expressions fully determine the root locus. Let the characteristic equation of a system be formula_1, where formula_2. Rewriting the equation in polar form is useful. where formula_5 are the only