Solid bounded by different region

[LCKurtz]

I think you need some face-to-face time with your teacher. I gather that English isn't your first language, but still, you don't seem to be understanding anything we are trying to tell you.

 

[Mark44]

I think you need some face-to-face time with your teacher. I gather that English isn't your first language, but still, you don't seem to be understanding anything we are trying to tell you.

I agree completely. We are more than 30 posts into this problem, and you still don't understand what the solid looks like, despite multiple graphs and explanations from LCKurtz and me.

 

[chetzread]

I think you need some face-to-face time with your teacher. I gather that English isn't your first language, but still, you don't seem to be understanding anything we are trying to tell you.

sorry , after looking it carefully ,the solid formed is the red part ? (refer to the attachment)
So , the red part represent the projection to xy plane ?

 

[chetzread]

here's my latest working . I use xy plane projection

 

[LCKurtz]

You have errors in your work. But you are supposed to do it in cylindrical coordinates anyway. You need $dz,~dr,~d\theta$ variables in your integrals.