Question

Find the area of the surface by rotating the curve y=2x , about the x axis (0 to 1).

the integral from a to b of 2pi(y)(ds)

Answer 1

\[\int\limits_{0}^{1} 2x \sqrt{5}\] I get that, but I end up with an incorrect result. Am I doing something wrong?

Answer 2

I guess the answer is 2*sqrt(5)*pi.
Good luck

Answer 3

well you've left the π out for starters....

Answer 4

usually it stay out, according to how I learned it.

Answer 5

there's no "circularity" without π!!!