Date | May 2018 | Marks available | 3 | Reference code | 18M.2.hl.TZ2.4 |
Level | HL only | Paper | 2 | Time zone | TZ2 |
Command term | Find | Question number | 4 | Adapted from | N/A |
Question
Consider the following diagram.
The sides of the equilateral triangle ABC have lengths 1 m. The midpoint of [AB] is denoted by P. The circular arc AB has centre, M, the midpoint of [CP].
Find AM.
Find A∧MP in radians.
Find the area of the shaded region.
Markscheme
METHOD 1
PC =√32 or 0.8660 (M1)
PM =12PC =√34 or 0.4330 (A1)
AM =√14+316
=√74 or 0.661 (m) A1
METHOD 2
using the cosine rule
AM2 =12+(√34)2−2×√34×cos(30∘) M1A1
AM =√74 or 0.661 (m) A1
[3 marks]
tan (A∧MP) =2√3 or equivalent (M1)
= 0.857 A1
[2 marks]
EITHER
12AM2(2A∧MP−sin(2A∧MP)) (M1)A1
OR
12AM2×2A∧MP−=√38 (M1)A1
= 0.158(m2) A1
Note: Award M1 for attempting to calculate area of a sector minus area of a triangle.
[3 marks]