I follow the instructions in the User Manual section 5.2:
Dragging to a Plot Region
To use the drag-and-drop method, use the plot region created by one of the other methods or insert an empty plot region into the document. Empty plot regions can be two-dimensional or three-dimensional.
Advantages of the drag-and-drop method include the ease of adding and removing plots and the independence from plotting command syntax.
1. From the Insert menu, select Plot, and then 2D.
2. Enter the expression sin(x) in an input region.
3. Select the full expression in the input region and drag it into the plot region.
4. Repeat steps 2 and 3 using the following expressions: sin(2*x), sin(x+2), and sin(x)^2.
5. To remove an expression from the plot region, drag-and-drop the expression plot from the plot region to a Maple input region.
But when I do 3. the expression disappears from the input region but nothing appears in the plot region.
Anybody know what I'm doing wrong?