Solutions:
(a) If we rotate the ellipsoid around the x-axis the surface area, S, is twice the area of that in the first quadrant.
Factoring out the from the square root,
and letting
Using a table of integrals (#30 in Stewart)
(b)
Set
Using a table of integrals (#21 in Stewart)
Computations with g:
Consequently:
This is the same as the answer in the book:
because
and
by: nl