Question

http://www.xtremepapers.com/CIE/International%20A%20And%20AS%20Level/9709%20-%20Mathematics/9709_s10_qp_13.pdf

help me in Question no.9 pls
reply quick thank you :)

Answer 1

First we need the points A and B, know how to find that?

Answer 2

yes i know that

Answer 3

A has (1,5) and B(4,5)

Answer 4

M(2,4)

Answer 5

right, so our integration will be from 1 to 4
what is the outer radius of each disk we will use in our method?
what is the radius of the inner disk?

Answer 6

i dont know how a cylinder is formed in this curve

Answer 7

we are making rings out of each section of areathe outer radius of each ring will be\[r_0=5\]the inner radius will be\[r_i=x+\frac{4}{x}\]the area of each disk wile therefor be\[\pi r_0^2-\pi r_i^2\to\pi(r_0^2-r_i^2)\]