PLZ HELP ME ANSWER THESE VOLUME OF ROTATIONS DIAGRAM/QUESTION IN 1 HOUR

The rest don't make sense so i say the first one.

To solve this integral, what you can do is split it up as follows: (1) ∫40(x2−4)dx=∫40(x2)dx−∫40(4)dx. to integrate  4  as an  indefinite integral, a good rule of thumb is  by  an equation below  for  polynomials; . (2) ∫xa=xa+1a+1+c , where a is any number. c denotes some constant that is crucial when doing 

Tgtgtgtgtgtgtgtgtgtg

Iwould say either b or ci could be wrong let me know