@@ -143,6 +143,7 @@ To plot a curve that is described by parametric equations, we compute the $$x$$
3. The file `main.cpp` (in Sources) contains the function `main()` where you will be adding code. Open this file and study the code.
```cpp
+
QApplication a(argc, argv);
XYPlotWindow wLine;
XYPlotWindow wCircle;