Date | May 2022 | Marks available | 3 | Reference code | 22M.1.AHL.TZ1.9 |
Level | Additional Higher Level | Paper | Paper 1 (without calculator) | Time zone | Time zone 1 |
Command term | Find | Question number | 9 | Adapted from | N/A |
Question
Consider the complex numbers and , where .
Find an expression for in terms of .
Hence, given that , find the value of .
Markscheme
M1
A1A1
Note: Award A1 for and A1 for .
[3 marks]
(M1)
EITHER
(since , for ) A1
OR
(or equivalent) A1
THEN
A1
[3 marks]
Examiners report
Part (a) was generally well done with many completely correct answers seen. Part (b) proved to be challenging with many candidates incorrectly equating the ratio of their imaginary and real parts to instead of . Stronger candidates realized that when , it forms an isosceles right-angled triangle and equated the real and imaginary parts to obtain the value of b .