FillCurve := proc(f,a,b,am,bm) local i,n,x1,x2,y1,y2,A,d: n := 200; d := ( b - a ) / n; x2 := a; for i from 1 to n do x1 := evalf( x2 ); x2 := evalf( a + i * d ); y1 := evalf( f( x1 ) ); y2 := evalf( f( x2 ) ); if ( y1 > 0 ) then A[i] := polygonplot( [ [x1, 0], [x1, y1], [x2, y2], [x2, 0] ], color=`::clr.2`, style=patchnogrid ); else A[i] := polygonplot( [ [x1, 0], [x1, y1], [x2, y2], [x2, 0] ], color=`::clr.3`, style=patchnogrid ); fi; od: display( [ plot( f(x), x = am..bm, color=`::clr.1`, discont=true ), seq( A[i], i=1..n ) ] ); end: FillCurve(x->`in`,`::fx.min`,`::fx.max`,`::x.min`,`::x.max`);