Manipulation Graphics

Questions
1

Hello,

I built a manipulation, but I can’t figure out how to add graphics. Here’s what I have so far:

Manipulate[Plot[((a/(1 - b)) + (b/(1 - b))*c), {c, 0, 100}, 
PlotRange -> {{0, 100}, {0, 300}}, AxesOrigin -> {0, 0}, 
AxesLabel -> {Xaxis, Yaxis}], {{a, 30}, 0, 50}, {{b, .6}, 0, 1}, {{c, 90}, 0, 100}]

How can I add dynamic dashed lines? For example, this demonstration has dashed lines from each axis to the curve(s): http://www.demonstrations.wolfram.com/BasicSupplyAndDemand/ … How do I add similar dashed lines to my manipulation?

The demonstration in the link above also has dynamic labels (P^e and Q^e). How do I add similar labels?

Thanks for your time. I appreciate your help.

2

Dear Edo,

the Demonstration project comes with the full code, so that you can see how it is done. You only need to adapt it to your problem and you get something like:

Manipulate[
 Plot[((a/(1 - b)) + (b/(1 - b))*c), {c, 0, 100}, 
  PlotRange -> {{0, 100}, {0, 300}}, AxesOrigin -> {0, 0}, 
  LabelStyle -> Directive[Bold, 14], AxesLabel -> {"Xaxis", "Yaxis"}, 
  Ticks -> {{{c/2, "Q"}}, {{
      ((a/(1 - b)) + (b/(1 - b))*c/2), "P"}}}, 
  Epilog -> {{Thick, Dashed, 
     Line[{{c/2, 
        0}, {c/2, ((a/(1 - b)) + (b/(1 - b))*c/2)}}]}, {Thick, Dashed,
      Line[{{c/
         2, ((a/(1 - b)) + (b/(1 - b))*
           c/2)}, {0, ((a/(1 - b)) + (b/(1 - b))*c/2)}}]}}], {{a, 30},
   0, 50}, {{b, .6}, .0000001, 1}, {{c, 90}, 0, 100}]

which I hope does what you want.

Cheers,

Marco

3

Perfect! Thanks so much Marco, that was really nice of you.