Date | November Example questions | Marks available | 3 | Reference code | EXN.2.SL.TZ0.2 |
Level | Standard Level | Paper | Paper 2 | Time zone | Time zone 0 |
Command term | Find | Question number | 2 | Adapted from | N/A |
Question
The following diagram shows a circle with centre O and radius 3.
Points A, P and B lie on the circumference of the circle.
Chord [AB] has length L and AˆOB=θ radians.
Show that arc APB has length 6π-3θ.
Show that L=√18-18 cos θ.
Arc APB is twice the length of chord [AB].
Find the value of θ.
Markscheme
* This sample question was produced by experienced DP mathematics senior examiners to aid teachers in preparing for external assessment in the new MAA course. There may be minor differences in formatting compared to formal exam papers.
EITHER
uses the arc length formula (M1)
arc length is 3(2π-θ) A1
OR
length of arc AB is 3θ A1
the sum of the lengths of arc AB and arc APB is 6π A1
THEN
so arc APB has length 6π-3θ AG
[2 marks]
uses the cosine rule (M1)
L2=32+32-2(3)(3) cos θ A1
so L=√18-18 cos θ AG
[2 marks]
6π-3θ=2√18-18 cos θ A1
attempts to solve for θ (M1)
θ=2.49 A1
[3 marks]