AP Calculus BC online/self study/help?

<p>So taking AB? Yeah, good luck! </p>

<p>Question guys, shell method…why is the p(x) always = to x?</p>

<p>On arc length and surfaces of revolution, is this formula s = c d integral sq rt 1 + {f’(x)}2 dy only used when you have an X= type function…? Same for surfaces of revolution…</p>