Here are a few Cocoa apps available for download.

**COMPLEX** is a little utility which accepts two complex numbers; user can select to get sum, product, or quotient. Complex

**SOLVE CUBIC** is a utility which does what it says. While the quadratic equation solution is a simple closed form expression, the cubic solution is not so simply calculated. While problems dealing with squares have been around since Egyptian and Babylonian times (property issues, etc.), it wasn't until 8th century BCE that they were formulated as equations. The first explicit solution of the quadratic equation was given by Brahmagupta in 628 BC. History of QF. During the period of the Renaissance, when mathematics was undergoing renewed interest and rebirth, It was initially thought that the solution to the general equation of third degree would be a straightforward extrapolation to that of the quadratic. This attitude was probably fostered by the fact that the quadratic had been dealt with long ago with more primitive mathematics. It was surprising then that the path to the cubic solution was protracted and difficult. It finally was conquered but not without drama and the need to extend mathematics. This fascinating history is covered in "The Equation That Couldn't Be Solved". The title 'equation' is not the cubic but the quintic. Solve Cubic

**WEIGHT AND BALANCE** is a utility program for the calculation of the permissable loading of a single engine, general aviation aircraft. It shows the total gross weight, loaded CG, and loaded CG graph for user inputs of fuel on board, pilot/passenger's weights, and baggage weight. New single engine aircraft models can be readily incorporated in the data base. This app is offered as a helpful tool and although it is accurate and correct, no liability to the author is recognized and user accepts any and all risk. User should verify program results with normal POH procedures for his/her aircraft. Weight & Balance

**MS COUPLED LINES** program is for the design analysis and synthesis of microstrip coupled lines. These are design elements regularly employed for directional couplers and band pass filters. MS Coupled Lines