<< Graphics`FilledPlot`
$TextStyle = {FontFamily -> "Times", 
        FontWeight -> "Bold", FontSize -> 16}

Problem01 = 
        FilledPlot[{Sqrt[1 - x^4], -Sqrt[1 - x^4]}, {x, -1, 1}, 
          AspectRatio -> Automatic, 
          Fills -> RGBColor[0.5, 0.5, 1]];

Problem02 = 
        FilledPlot[{0, 1 - x^2}, {x, -1, 1}, 
          AspectRatio -> Automatic, 
          Fills -> RGBColor[0.5, 0.5, 1]];

Problem03 = 
        Plot[{2 - Sqrt[16 - 4  x^2], 2 + Sqrt[16 - 4  x^2]}, {x, -2, 2}, 
          AspectRatio -> Automatic, 
          PlotStyle -> {{RGBColor[0.5, 0.5, 1], 
                AbsoluteThickness[2]}}];

Problem04 = 
        Plot[{1 + 2  Sqrt[1 - x^2], 1 - 2  Sqrt[1 - x^2]}, {x, -1, 1}, 
          AspectRatio -> Automatic, 
          PlotStyle -> {{RGBColor[0.5, 0.5, 1], 
                AbsoluteThickness[2]}}];

Problem05 = 
        FilledPlot[{Sqrt[
              1 - (1 - Sqrt[4 - x^2])^2], -Sqrt[
                1 - (1 - Sqrt[4 - x^2])^2]}, {x, -2, 2}, 
          AspectRatio -> Automatic, 
          Fills -> RGBColor[0.5, 0.5, 1]];

Problem06 = 
        FilledPlot[{1 + Sqrt[x^2 + 3], 3, 
            1 - Sqrt[x^2 + 3], -1}, {x, -1, 1}, 
          AspectRatio -> Automatic, 
          Fills -> {{{1, 2}, RGBColor[0.5, 0.5, 1]}, {{3, 4}, 
                RGBColor[0.5, 0.5, 1]}}];

March 7,  2007