Question 1010999
Find a parametric representation of the surface x^2+y^2+z^2=9
Show all your work/solution step by step.
<pre>
That's the surface of a sphere with center (0,0,0) and radius 3, 
which is the graph of the semicircle 
{{{z =sqrt(9-x^2)}}} {{{-3<=x<=3}}}, {{{0<=phi<2pi}}} 

rotated about the z-axis.  Its parametrization is the vector 
function:

{{{r(u,phi)}}}{{{""=""}}}{{{matrix(1,7,"<",u*cos(phi),",",u*sin(phi),",",sqrt(9-u^2),">")}}}

Edwin</pre>