Date | November 2015 | Marks available | 4 | Reference code | 15N.2.sl.TZ0.1 |
Level | SL only | Paper | 2 | Time zone | TZ0 |
Command term | Find | Question number | 1 | Adapted from | N/A |
Question
The following diagram shows a circle with centre O and radius 3 cm.
Points A, B, and C lie on the circle, and AˆOC=1.3 radians.
Find the length of arc ABC.
Find the area of the shaded region.
Markscheme
correct substitution (A1)
egl=1.3×3
l = 3.9 (cm) A1 N2
[2 marks]
METHOD 1
valid approach (M1)
egfinding reflex angle, 2π−CˆOA
correct angle (A1)
eg2π−1.3, 4.98318
correct substitution (A1)
eg12(2π−1.3)32
22.4243
area=9π−5.85 (exact), 22.4 (cm2) A1 N3
METHOD 2
correct area of small sector (A1)
eg12(1.3)32, 5.85
valid approach (M1)
egcircle − small sector, πr2−12θr2
correct substitution (A1)
egπ(32)−12(1.3)32
22.4243
area=9π−5.85 (exact), 22.4 (cm2) A1 N3
[4 marks]
Total [6 marks]