sage: plot(e^(-x)*sin(x),(x,1,10))
<html><font color='black'><img src='cell://sage0.png'></font></html>
sage: plot(e^(-x)*sin(x)+exp(x),(1,10)) + plot(e^(-x)*sin(x),(x,1,10))
<html><font color='black'><img src='cell://sage0.png'></font></html>