I have been trying to combine two plots using Show. Everything looks fine, but the arrow from one of the plots does not show. What am I doing wrong here?

qw = 
  Plot[y /. Solve[(x/20)^2 + (y/10)^2 == 1], {x, -36, 35}, 
    AspectRatio -> Automatic, 
    PlotRange -> {{-37, 35}, {-16, 16}}, 
    PlotStyle -> {RGBColor["#123c69"]}, 
    Ticks -> Automatic, 
    Axes -> True];

Aq = 
  Plot[-a/((x^4)) - b, {x, -21, -35}, 
    PlotRange -> {{-36, -21}, {-6.5, -9.5}}, 
    PlotStyle -> {RGBColor["#ac3b61"]}, 
    Epilog -> 
       Arrow[{{-35, -((3151 Sqrt[7])/1250)}, {-35.7, -6.640033236810056}}]}];

Show[qw, Aq]

closed as off-topic by m_goldberg, Carl Lange, MarcoB, user42582, garej May 27 at 13:45

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This question arises due to a simple mistake such as a trivial syntax error, incorrect capitalization, spelling mistake, or other typographical error and is unlikely to help any future visitors, or else it is easily found in the documentation." – m_goldberg, Carl Lange, MarcoB, user42582, garej
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  • 4
    $\begingroup$ Use Show[qw, Aq, Epilog -> ...] instead of putting the Epilog inside of the second Plot function. $\endgroup$ – Carl Woll May 25 at 15:18

The options are always taken from the first object in Show. For example, you've specified PlotRange for both but the one that's being used with Show is the first one. It works like this for all options, including Epilog. You'll see the arrow if you change the order:

Show[Aq, qw]

but then, of course, the plot range will not be the same anymore. That's why it is sometimes necessary or useful to supply options to Show, which overrides the options given by the first argument. In this case,

Show[qw, Aq, 
 Epilog -> {RGBColor["#ac3b61"], 
   Arrow[{{-35, -((3151 Sqrt[7])/
         1250)}, {-35.7, -6.640033236810056}}]}]

shoud do it, as Carl noted in a comment.


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