# Solve an equation with a Piecewise function?

GROUPS:
 Hello I'm new to Mathematica, though I know a few about it. I'm trying to find a group of 2 values for Piecewise function changing with x, but I constantly have a problem with Solve producing a lot of errors can you tell me where is my mistake in this ? Whole thing is in attached file, Basically its: F(x)=Piecewise[...](x,wl,wp) Solve[MaxValue[F,x]/MinValue[F,x]==1.15,{wl,wp}] Or CylindricalDecomposition[1.1<=MaxValue[F,x]/MinValue[F,x]<=1.2,{wl,wp}] So I'm trying to get wl and wp values for optimization, but certainly I'm doing something wrong, please help. Attachments:
1 year ago
5 Replies
 That seems to be sort of a difficult problem. I changed your functions to make sure that all parameters are reaching the actual calculation. But I too got lots of errors. So I tried to get som ideas about the magnitude of the numbers involved. Unfortunately I did not find any reasonable approximation of the solution you are looking for. See notebook. Do you have any ideas about the magnitude of wl and wp? Attachments:
1 year ago
 Perhaps it may be helpful to get an impression of the behaviour of your function (as defined in the notebook attached to my last post) Animate[Plot3D[ff[x, u, v], {u, -5, 5}, {v, -5, 5}, PlotRange -> {-10^4, 10^4}], {x, 0, 20, .1}] 
 And this is interesting as well...... Manipulate[ Plot[ff[x, u, v], {x, -2, 10}, PlotStyle -> {Thick, Red}], {{u, 0}, -5, 5}, {{v, 0}, -5, 5}] Maybe it gives a clue to the solution of the original question.