Definition of a Function. A function is a relation for which each value from the set the first components of the ordered pairs is associated with exactly one value from the set of second components of the ordered pair. Okay, that is a mouth full.
Master cylinder without booster. Single bore master cylinders: These unboosted hydraulic Master Cylinders are actuated by foot effort, via the brake pedal. The brake pressure is related to actuation force and depends on the piston bore size: the smaller the bore, the higher the pressure.
A booster combined with a master cylinder (refer to Figure 1) forms thehydraulic brake actuation unit. A typical assembly is shown in Figure 1. The booster reduces thepedal effort required to apply the brakes as compared to a non-power system.