### Applet: A parametrized helicoid

#### Applet loading

The function $\dlsp(\spfv,\spsv) = (\spfv\cos \spsv, \spfv\sin \spsv, \spsv)$ parametrizes a helicoid when $0 \le \spfv \le 1$ and $0 \le \spsv \le 2\pi$. You can drag the cyan and magenta points on the sliders to change the values of $\spfv$ and $\spsv$. Or, you can drag the blue point on the helix directly, which will then change $\spfv$ and $\spsv$ so that the blue point is at $\dlsp(\spfv,\spsv)$. If you leave $\spfv$ fixed and change only $\spsv$, then the blue point traces out a helix with radius given by $\spfv$. If you keep $\spsv$ constant and change only $\spfv$, the blue point traces out a straight line.

#### Applet links

This applet is found in the pages

#### Notation systems

More information on notation systems

#### General information about three.js applets

The applet was made using three.js and requires Javascript as well as a browser that supports WebGL. For most three.js applets, you can drag with the mouse to rotate the view, drag with the right button to pan, and zoom in/out with the mouse wheel. Many applets contain points that you can drag to change values of variables.