Question

The given curve is rotated about the y-axis. Find the area of the resulting surface.

x = 

a2 − y2

,    0 ≤ y ≤ a/3

 

Answer 1

Step 1:

The curve is , .

If the curve is rotating about axis, area of the resultant surface is .

Where

.

 

Step 2:

Substitute and    in area formula.

Solution:

The area of the surface is  Sq-units.