Consider a sphere, $x^2+y^2+z^2=9.$

$($a$)(4$ pts$)$ Parameterize the surface of a sphere, $x^2+y^2+z^2=9$ using two parameter $$ and $.$

$($b$)(8$ pts$)$ Use the formula,

$A(G)={}_R||r_u(u,v)r_{?}$

$u(u,v)||dA$ for $(u,v)inR,$ to find the surface area of the sphere.