Here's my question:
Find the area of the surface created by the complete curve r=a when it is completely revolved about the x axis.Do not assume the formula for the surface area of a sphere.
Just by looking at it I did:
Mr F says: *Ahem* You're rotating a circle around the x-axis. This gives a sphere. You do recall that the surface area of a sphere is , don't you?
Which was incorrect.
Mr F says: Obviously.
So then I did it the way I think I was supposed to:
and this answer was also wrong. The book gave the answer as:
What's going wrong??