Inserting formula into plot

What's a standard way to insert formula into Plot?

My plot is below. I'd like to have the formula of the plot nicely formatted and inserted into plot. TraditionalForm looks OK, but it puts the formula in one line, whereas I want a two-line fraction.

Plot[{1, (开发者_如何学Go\[CapitalDelta] - 1)^(\[CapitalDelta] - 
   1)/(\[CapitalDelta] - 2)^\[CapitalDelta]}, {\[CapitalDelta], 3, 6},
  PlotRange -> {0, 4}, PlotStyle -> {Dashing[.02], Thick}, 
 AxesLabel -> {"\[CapitalDelta]", "\[Lambda]"}]

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Sorry for being late :D. I mostly use a simplified version of Leonid's answer. Not sure if it is general enough for any purpose, but certainly works here.

Plot[{1, (\[CapitalDelta] - 1)^(\[CapitalDelta] - 
      1)/(\[CapitalDelta] - 2)^\[CapitalDelta]}, {\[CapitalDelta], 3, 
  6}, PlotRange -> {0, 4}, PlotStyle -> {Dashing[.02], Thick}, 
 AxesLabel -> {"\[CapitalDelta]", "\[Lambda]"}, 

Epilog -> Inset[HoldForm@TraditionalForm[

   (\[CapitalDelta] - 1)^(\[CapitalDelta] - 1)/
   (\[CapitalDelta] - 2)^\[CapitalDelta]]]]  

Or use Epilog -> Inset[Panel@HoldForm@TraditionalForm... for a nice box around the function:

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Perhaps this could get you started?

Plot[{1,(\[CapitalDelta]-1)^(\[CapitalDelta]-1)/(\[CapitalDelta]-2)^\[CapitalDelta]}, 
{\[CapitalDelta],3,6},PlotRange->{0,4},
PlotStyle->{Dashing[.02],Thick},AxesLabel->{"\[CapitalDelta]","\[Lambda]"},
Epilog->Inset[Style[
   HoldForm@@MakeExpression@MakeBoxes@TraditionalForm[(\[CapitalDelta]-1)^
   (\[CapitalDelta]-1)/(\[CapitalDelta]-2)^\[CapitalDelta]],10]]]