Here is a code that works well:

`f1[x_] := Sqrt[25 - x^2] Manipulate[ Plot[f1[x], {x, from, to}, AspectRatio -> Automatic, PlotRange -> {{-20, 20}, {-20, 20}}, Epilog -> {Text["From y: " <> ToString[f[from]], Scaled[{1, 1}], {1, 1}], Text["To y: " <> ToString[f[to]], Scaled[{1, 0.96}], {1, 1}]}], {{from, -10, "from x"}, -10, 10, Appearance -> "Labeled"}, {{to, 10, "to x"}, -10, 10, Appearance -> "Labeled"}] `

output like:

Now I want to plot 2 functions at the same time. I tryied something like this:

`f1[x1_] := Sqrt[25 - x1^2] f2[x2_] := -Sqrt[25 - x2^2] Manipulate[ Plot[{f1[x1_], f2[x2_]}, {x1, from1, to1}, {x2, from2, to2}, AspectRatio -> Automatic, PlotRange -> {{-20, 20}, {-20, 20}}, Epilog -> {Text["From y1: " <> ToString[f[from1]], Scaled[{1, 1}], {1, 1}], Text["To y1: " <> ToString[f[to1]], Scaled[{1, 0.96}], {1, 1}]}, Epilog -> {Text["From y2: " <> ToString[f[from2]], Scaled[{1, 1}], {1, 1}], Text["To y2: " <> ToString[f[to2]], Scaled[{1, 0.96}], {1, 1}]}], {{from1, -10, "from1 x"}, -10, 10, Appearance -> "Labeled"}, {{to1, 10, "to x"}, -10, 10, Appearance -> "Labeled"}, {{from2, -10, "from2 x"}, -10, 10, Appearance -> "Labeled"}, {{to2, 10, "to2 x"}, -10, 10, Appearance -> "Labeled"}] `

But it does not plots anything. How to correct my code above?