\documentclass[12pt]{article}
\usepackage{pstricks}
\usepackage{pstricks-add}
\pagestyle{empty}
\parindent=0pt
\begin{document}

\def\pshlabel#1{\footnotesize#1}\def\psvlabel#1{\footnotesize#1}
\psset{unit=1.5cm}
\begin{pspicture}[plotpoints=200](-0.5,-3)(10,2.5) 
  \psStep[algebraic,fillstyle=solid,fillcolor=yellow](0.001,9.5){40}{2*sqrt(x)*cos(ln(x))*sin(x)}
  \psStep[algebraic,StepType=Riemann,fillstyle=solid,fillcolor=blue](0.001,9.5){40}{2*sqrt(x)*cos(ln(x))*sin(x)}
  \psaxes{->}(0,0)(0,-2.75)(10,2.5)
  \psplot[algebraic,linecolor=white]{0.001}{9.75}{2*sqrt(x)*cos(ln(x))*sin(x)}
  \uput[90](6,1.2){$f(x)=2\cdot\sqrt{x}\cdot\cos{(\ln{x})}\cdot\sin{x}$}
\end{pspicture}

\end{document}
