# Determine the surface area

## Homework Statement

Find the surface area of the solid obtained by rotating
y = √9 − X^2 , − 2 ≤ X ≤ 2 about the X-axis.

∏r^2

## The Attempt at a Solution

Y = (9 - x^2)^-1/2
Is that can do like this..
then how bout the power inside the X^2??

## The Attempt at a Solution

mfb
Mentor
∏r^2
That formula applies to circles only.

There is a general formula for surface areas of rotated functions. It is possible to derive it, but usually this is not expected for those tasks, so I think the formula is given somewhere.

Alternatively, draw a sketch of the function. Rotated around the x-axis, it is a well-known object where the surface is easy to calculate.