) plot2d (sin(x)/x, [x, -20, 20])$
</pre><p><div class="image"><img src="./../figures/introduction1.gif" alt="../figures/introduction1"></div>
</p><pre class="example">(%i2) plot2d ([atan(x), erf(x), tanh(x)], [x, -5, 5], [y, -1.5, 2])$
</pre><p><div class="image"><img src="./../figures/introduction2.gif" alt="../figures/introduction2"></div>
</p><pre class="example">(%i3) plot3d (sin(sqrt(x^2 + y^2))/sqrt(x^2 + y^2), 
         [x, -12, 12], [y, -12, 12])$
</pre><p><div class="image"><img src="./../figures/