Solving Algebraic and Transcendental Equations: An Example
As an example of an algebraic equation, consider the equation f(u) = 0 for
This equation has a single real-valued root at u = 1.
1
In the Model Builder, click the Global Equations node in a Global ODEs and DAEs interface.
2
In the Settings window for Global Equations, enter u in the Name column and u^3+u-2 in the f(u,ut,utt,t) column (both entries on the same row).
3
Solve this using a stationary solver.
4
In the Settings window for State variable u (Global Evaluation), click the Evaluate button (), and the value of the root displays in the Table window.
As an example of a transcendental equation, consider the equation f(u) = 0 for
A root to this equation is approximately 0.56714. To enter it for the node:
1
In the Model Builder, click the Global Equations node.
2
Enter u in the Name column and exp(-u)-u in the f(u,ut,utt,t) column (both entries on the same row).
3
Compute the solution.
4
In the Settings window for State variable u (Global Evaluation), click the Evaluate button (), and the value of the root (rounded to 0.56714) displays in the Table window.
Derived Values and Tables