E field calculation for q sphere

[fisher garry]

Homework Statement

I have managed to come up until the equation underlined with orange

Relevant Equations

Look at the answer sheet

I have some questions about this answer. Why do they use absolute value when writing in the limits in the integral underlined with orange?
And how do they get from this value where I have underlined with orange to the answer for E outside the sphere. Can someone do the rewriting?
And last why is the E field 0 inside the sphere? Is it related to the calculations or not? Can anyone explain why it is 0?

I am using this to try to derive gauss law without the divergence theorem

 

[berkeman]

Is there a reason that your attached image is so fuzzy? Can you link to the source?

 

[fisher garry]

I have scanned Griffiths introduction to electrodynamics onto my computer (I have bought two copies of the book). I marked the equality sign in the question. What else is unclear? Is it the question or the answer?

 

[berkeman]

What else is unclear?

The image is extremely fuzzy, and it is problematic for you to ask us to squint our eyes to try to decode it. Please post a much clearer scan or image. Thank you.

 

[fisher garry]

here is a different answer. Albeit my questions are in thefirst image in my original post. But this is the same assignment