Double Integrals on a Sphere: Solving for f(x,y,z) and g(t)

[myfunkymaths]

Homework Statement

f(x,y,z) = g(√(x^2 + y^2 + z^2))
g(t) = t-5
evaluate ∯ f(x,y,z)ds

where S is sphere x^2 + y^2 + z^2 = 9

Homework Equations

The Attempt at a Solution

i don't know how to go about it. can someone help me with this, how to approach this from start to end. i will solve it, but i need to know the steps in doing it.

 

[tiny-tim]

hi myfunkymaths!

(have a square-root: √ and try using the X² icon just above the Reply box )

f(x,y,z) = g(√(x^2 + y^2 + z^2))
g(t) = t-5
evaluate ∯ f(x,y,z)ds

where S is sphere x^2 + y^2 + z^2 = 9

uhh? isn't that just integrating r - 5 over the sphere r = 3 ?

 

[myfunkymaths]

hi myfunkymaths!

(have a square-root: √ and try using the X² icon just above the Reply box )


uhh? isn't that just integrating r - 5 over the sphere r = 3 ?

so what function do i integrate twice? and with what bounds was it

 

[tiny-tim]

but it's constant!