Date | May 2021 | Marks available | 7 | Reference code | 21M.1.AHL.TZ2.2 |
Level | Additional Higher Level | Paper | Paper 1 (without calculator) | Time zone | Time zone 2 |
Command term | Solve | Question number | 2 | Adapted from | N/A |
Question
Solve the equation 2 cos2 x+5 sin x=4, 0≤x≤2π.
Markscheme
attempt to use cos2 x=1-sin2 x M1
2 sin2 x-5 sin x+2=0 A1
EITHER
attempting to factorise M1
(2 sin x−1)(sin x−2) A1
OR
attempting to use the quadratic formula M1
sin x=5±√52-4×2×24(=5±34) A1
THEN
sin x=12 (A1)
x=π6, 5π6 A1A1
[7 marks]
Examiners report
[N/A]