CAIE A-Level Mathematics 1.4.1 Radians

CAIE A-Level Mathematics 1.4.1 Radians
Cambridge International AS & A Level Mathematics 9709 syllabus for exams in 2028, 2029 and 20302028–2030

Practise finding angles in radians from diagrams, symmetry and trigonometry, including exact multiples of π and decimal answers.

How this is tested

  • use symmetry, sine, cosine rule or right-triangle ratios to justify angles in radians
  • convert degree working into radians and state exact fractions of π where required

Question 6(a)

[Maximum number: 1]
Figure for Question 6(a) — CAIE A-Level Mathematics

The diagram shows a motif formed by the major arc A B of a circle with radius r and centre O, and the minor arc⁡AOB\operatorname{arc} A O B of a circle, also with radius r but with centre C. The point C lies on the circle with centre O.

Given that angle ACB=kπA C B=k \pi radians, state the value of the fraction k.