Question

http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Mathematics%20(9709)/9709_s09_qp_1.pdf
number (i)
can anyone help!

Answer 1

Its 5(i)
mis type

Answer 2

Perimeter of R1 = length of major arc AB

First, find Perimeter of R1 = 2 radii + minor arc AB\[\Large =2 r + \theta r\]

length of major arc AB = \[\Large (2 \pi - \theta) * r\]

Answer 3

Set them equal and solve for theta\[\Large 2 r + \theta r = (2 \pi - \theta) * r\]
You can factor out r on the left...\[\Large r(2 + \theta ) =r (2 \pi - \theta) \]

Answer 4

Follow up to here...? You can now solve for theta.

Answer 5

thnx.. :)

Answer 6

Still, confused.. how did u come with (length of major arc AB =
(2π−θ)∗r)

Answer 7

Since you want the major angle for that arc, you have to subtract the smaller angle from 360 degrees (or 2pi)
Then use arc length = θr (for θ in radians)