Date | May 2017 | Marks available | 3 | Reference code | 17M.1.AHL.TZ1.H_5 |
Level | Additional Higher Level | Paper | Paper 1 (without calculator) | Time zone | Time zone 1 |
Command term | Find | Question number | H_5 | Adapted from | N/A |
Question
ABCD is a parallelogram, where →AB = –i + 2j + 3k and →AD = 4i – j – 2k.
Find the area of the parallelogram ABCD.
By using a suitable scalar product of two vectors, determine whether AˆBC is acute or obtuse.
Markscheme
* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.
→AB×→AD=−i +10j – 7k M1A1
area=|→AB×→AD| = √12+102+72
=5√6(√150) A1
[3 marks]
METHOD 1
→AB∙→AD=−4−2−6 M1A1
=−12
considering the sign of the answer
→AB∙→AD<0, therefore angle DˆAB is obtuse M1
(as it is a parallelogram), AˆBC is acute A1
[4 marks]
METHOD 2
→BA∙→BC=+4+2+6 M1A1
=12 considering the sign of the answer M1
→BA∙→BC>0⇒AˆBC is acute A1
[4 marks]