anonymous 5 years ago Find the surface area generated by rotating the given curve about the y-axis. x = et - t y = 4et/2 0 ≤ t ≤ 1 I'm pretty sure the formula should be something like an integral of sqrt( (y'(t))^2 + (x'(t))^2 ) dt But i could be wrong

1. anonymous

$\S=\int\limits_{a}^{b} 2pix \sqrt{(dx/dt)^2+(dy/dt)^2}dt$

2. anonymous

What does the x do?

3. anonymous

that is the radius of the generated circular figure

4. anonymous

So x should be a function?

5. anonymous

Yea a function in respect to t

6. anonymous

Coool, actually i thought there was more to this one with the limits, but i guess it's just 0 to 1

7. anonymous

yea it is just 0 to 1 because everything is in repsect to t

8. anonymous

The integral looks like a good time.. lol

9. anonymous

um in some cases u might not be able to solve the intergral haha