Please write out all steps so I can learn Evaluate the integ

Please write out all steps so I can learn! Evaluate the integral of (x^2 + y^2)z^2 over part of the cylinder x^2 + y^2 <= 1 inside the sphere x^2 + y^2 + z^2 = 4

Solution

x2+y2+z2=4,

z=-[4 -(x2+y2)],z=[4 -(x2+y2)]

in cylindrical coordinates

x=rcos y=rsin

x2+y2=r2

z=-[4 -(r2)] , z=[4 -(r2)]

x2+y2<=1

r2<=1

0<=r<=1

0<=<=2,0<=r<=1 ,-[4 -(r2)]<=z<=[4 -(r2)]

dv =r dz dr d

   (x2+y2)z2 dv

= [0 to 2]  [0 to 1] [-[4 -(r2)] to [4 -(r2)]](r2)z2 r dz dr d

= [0 to 2]  [0 to 1] [-[4 -(r2)] to [4 -(r2)]] (1/3)r3z3 dr d

= [0 to 2]  [0 to 1] (1/3)r3[([4 -r2])3 - (-[4 -r2])3] dr d

= [0 to 2]  [0 to 1] (2/3)r3([4 -r2])3 dr d

= [0 to 2]  [0 to 1] (1/3)r2([4 -r2])3 2r dr d

let 4 -r2=u=>r2=4-u =>2r dr =-du, r =0 =>u =4 , r =1=>u =3

= [0 to 2]  [4 to 3] (1/3)(4-u)(u)3 (-du) d

= [0 to 2]  [3 to 4] (1/3)(4-u)u3/2du d

= [0 to 2]  [3 to 4] (1/3)(4u3/2-u5/2)du d

= [0 to 2]  [3 to 4] (1/3)(4(2/5)u5/2-(2/7)u7/2) d

= [0 to 2]  [3 to 4] (2/3)((4/5)u5/2-(1/7)u7/2) d

= [0 to 2]  (2/3)((4/5)45/2-(1/7)47/2) -(2/3)((4/5)35/2-(1/7)37/2) d

= [(2/3)((4/5)45/2-(1/7)47/2) -(2/3)((4/5)35/2-(1/7)37/2) ](2-0)

= [((4/5)45/2-(1/7)47/2) -((4/5)35/2-(1/7)37/2) ](4/3)

=6.385


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