Describe a new [b]parametric surface[/b] by defining [math]x(u,v)[/math], [math]y(u,v)[/math], and [math]z(u,v)[/math] and changing the starting and ending [math]u[/math] and [math]v[/math] values. See the companion video at [url]https://youtu.be/aHziHgXOkjc[/url][br][list][br][*] The blue slider value will highlight a specific [b]grid curve[/b] for a fixed [math]u[/math] value.[br][*] The red slider value will highlight a specific [b]grid curve[/b] for a fixed [math]v[/math] value.[br][/list]

After watching the video, try parametrizing a donut!