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**1. Homework Statement**

Hi,

I have this problem:

the surfaces r=2 and 4, [math]\theta=[/math]30 degrees and 50 degrees, [math]\phi=[/math]20 degrees and 60 degrees identify a closed surface.

1- find the enclosed volume.

2- Find the total area of the enclosed

__surface__. ( I think it is a typo from the teacher. It is

**volume**not surface)

The first question is straigth forward

For the secon question I have some issues.

**2. Homework Equations**

Do I need to take take each element of surface (in spherical coordinates)

dS1=[tex]r^2[/tex] sin(theta) [tex]d\theta[/tex] [tex]d\phi[/tex]

dS2=[tex]r[/tex]*[tex]dr[/tex][tex]d\phi[/tex]

dS3=[tex]\sin\theta[/tex]*[tex]r[/tex][tex]dr[/tex][tex]d\phi[/tex]

**3. The Attempt at a Solution**

integrate the according the limits and the total are should be

S= S1+S2+S3

Is my reasonnig correct?

Thank you

B

**1. Homework Statement**

**2. Homework Equations**

**3. The Attempt at a Solution**

**1. Homework Statement**

**2. Homework Equations**

**3. The Attempt at a Solution**

**1. Homework Statement**

**2. Homework Equations**

**3. The Attempt at a Solution**

**1. Homework Statement**

**2. Homework Equations**

**3. The Attempt at a Solution**

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