Exercises for which drop-down lists are very practical to are combination exercises. In next applet you have to combine four graphs and their equations.

[list][*][b]four functions[/b][br]- Create four functions, save each graph as a picture and insert the four pictures.[br]- Add the texts A, B, C and D under the four pictures to identify the graphs.[br]- Create four texts with the equations of the four functions, sorted differently than the graphs.[/*][*][b]four lists[/b][br]- Create list1, list2, list3 and list4 as [code]{"", "A", "B", "C", "D"}[/code][br]- Select in the Basic tab of the Properties the option [code]Draw as drop-down lists[/code] to show them.[/*][*][b]four answers[/b]: Create[br]- [code]ans1 = SelectedIndex(list1)[/code] and likewise ans2, ans3 and ans4 [/*][*][b]Control[/b]: Define the dynamic colors if the drop-down list according to the right combinations[br]- The color should turn Red if the selection is not blank and not equal to the right function.[br]- The color should turn Green if the selection fits the function. [br] Since the equation f[sub]1[/sub] fits to D (= the fith option of the list) we get for the first list:[br][code] [/code][code]Red: If((ans1 ≠ 1) ∧ (ans1 ≠ 5), 1, 0) [br] Green: If(ans1 ≟ 5, 0.7, 0)[br] Blue: 0[/code][/*][*][b]Button[/b]: Create a button to reset all lists to their initial position (= blank) with the script[br][code]SetValue[list1,1][br]SetValue[list2,1][br]SetValue[list3,1][br]SetValue[list4,1][/code][br][/*][/list]