Date | November 2019 | Marks available | 6 | Reference code | 19N.2.AHL.TZ0.H_6 |
Level | Additional Higher Level | Paper | Paper 2 | Time zone | Time zone 0 |
Command term | Find | Question number | H_6 | Adapted from | N/A |
Question
Let , where and .
One of the roots of is . Find the value of .
Markscheme
METHOD 1
one other root is A1
let third root be (M1)
considering sum or product of roots (M1)
sum of roots A1
product of roots A1
hence A1
METHOD 2
one other root is A1
quadratic factor will be (M1)A1
M1
comparing coefficients (M1)
hence A1
METHOD 3
substitute into (M1)
(M1)A1
equating real or imaginary parts or dividing M1
or or A1
hence A1
[6 marks]
Examiners report
[N/A]
Syllabus sections
Topic 1—Number and algebra » AHL 1.14—Complex roots of polynomials, conjugate roots, De Moivre’s, powers & roots of complex numbers
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