Generation of inverse functions by the method of steepest descent

The technique of steepest descent can be used to generate the inverse of a function with standard analog or hybrid computer components. The resulting system is often free from the instability problems that plague inverse function generation by implicit computation. When the method is applied to forming division from multiplication a four-quadrant divider results. Neither of the two most common penalty functions, error squared and absolute error produce wholly satisfactory operation. If the loop gain is allowed to increase without bound, it causes relay or bang-bang type of performance that is free from the objectionable response of the previous systems.