Electric Potential and Gauss' Laws Stuff (I think)

[I Am Robot]

Homework Statement

[PLAIN]http://img203.imageshack.us/img203/5679/physics2h.png

Homework Equations

Included above I believe...

The Attempt at a Solution

a) i think dq=$$\lambda$$2$$\pi$$dy

Some of the calculus that we are using I am shaky on and I just don't understand what is being asked here. The others I really am not sure of. I am trying to develop a better understanding but my school offers no tutoring and my professor is virtually a robot.
\

 

[SammyS]

Homework Statement

[PLAIN]http://img203.imageshack.us/img203/5679/physics2h.png

Homework Equations

Included above I believe...

The Attempt at a Solution

a) i think dq=$$\lambda$$2$$\pi$$dy

Some of the calculus that we are using I am shaky on and I just don't understand what is being asked here. The others I really am not sure of. I am trying to develop a better understanding but my school offers no tutoring and my professor is virtually a robot.
\

You wrote dq=λ2π dy.

Where does the 2π come from?