1. O is the origin and A is the point on the curve y=tan x where

Calculate the area of the region R enclosed by the arc OA, the x-axis and the line

, giving your answer in EXACT form. Hence, find

in EXACT form.

Then, the region S is enclosed by the arc OA, the y-axis ad the line

.

*Find the volume of the solid of revolution formed when S is rotated through * * about the x-axis, giving your answer in EXACT form.*

for qn 1 :

i can do the first part....my ans is

i can do the second part too by using integration by parts....my ans is

then I don't know how to do the last part. if it is rotated about y-axis , then i know, but it is rotated about the x-axis.

then ...i'm stuck....