Question

surface area when y = 1/4 X^2 - 1/2 lnx is revolved about the y axis.

Answer 1

between what values of x or y?

Answer 2

1<x<2

Answer 3

Ok, so in general for a function y = f(x) what is the surface area of rotation for x between a and b? What is the integral we want to evaluate?

Answer 4

i got to ds = 2\[2\pi \int\limits_{1}^{2}x \sqrt{1 + (x - 1/x)^{2}}\]

Answer 5

Now are you rotating about the x axis or y axis?

Answer 6

y axis