For the application, the number of equations is necessary equal to the number of unknowns. In app number of unknowns automatically are input after input number of equations.
The app use dynamically entered equations. The equations are entered as strings using the operators +, -, /, *, sin(t), cos(t), pow(t,n), log(t), and others. The unknowns are input as x1, x2..., here is a correctly entered equation: x1*x1 – sin(x2)-37 for equation x1*x1 – sin(x2)-37=0. The app issues message: “Error: operator is unknown for token” if equation is not correct.
The application has functions for creating, storing, deleting, and saving the systems of nonlinear equations. Each such system is stored under its own name.
The list of systems is shown in a drop down list. After selecting an item(system) from it – list of equations of the system are appear on screen , there is a button to calculate the solution of the corresponding nonlinear system, and the solution is displayed in a table. The solution can be saved in file in selected device directory – screen shot start6.