Date | May Specimen paper | Marks available | 4 | Reference code | SPM.1.AHL.TZ0.11 |
Level | Additional Higher Level | Paper | Paper 1 (without calculator) | Time zone | Time zone 0 |
Command term | Show that | Question number | 11 | Adapted from | N/A |
Question
Let the roots of the equation be , and .
On an Argand diagram, , and are represented by the points U, V and W respectively.
Express in the form , where and .
Find , and expressing your answers in the form , where and .
Find the area of triangle UVW.
By considering the sum of the roots , and , show that
.
Markscheme
attempt to find modulus (M1)
A1
attempt to find argument in the correct quadrant (M1)
A1
A1
[5 marks]
attempt to find a root using de Moivre’s theorem M1
A1
attempt to find further two roots by adding and subtracting to the argument M1
A1
A1
Note: Ignore labels for , and at this stage.
[5 marks]
METHOD 1
attempting to find the total area of (congruent) triangles UOV, VOW and UOW M1
Area A1A1
Note: Award A1 for and A1 for
= (or equivalent) A1
METHOD 2
UV2 (or equivalent) A1
UV (or equivalent) A1
attempting to find the area of UVW using Area = × UV × VW × sin for example M1
Area
= (or equivalent) A1
[4 marks]
+ + = 0 R1
A1
consideration of real parts M1
explicitly stated A1
AG
[4 marks]