Date | November 2017 | Marks available | 2 | Reference code | 17N.1.SL.TZ0.T_10 |
Level | Standard Level | Paper | Paper 1 | Time zone | Time zone 0 |
Command term | Find | Question number | T_10 | Adapted from | N/A |
Question
Emily’s kite ABCD is hanging in a tree. The plane ABCDE is vertical.
Emily stands at point E at some distance from the tree, such that EAD is a straight line and angle BED = 7°. Emily knows BD = 1.2 metres and angle BDA = 53°, as shown in the diagram
T is a point at the base of the tree. ET is a horizontal line. The angle of elevation of A from E is 41°.
Find the length of EB.
Write down the angle of elevation of B from E.
Find the vertical height of B above the ground.
Markscheme
* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.
Units are required in parts (a) and (c).
EBsin53∘=1.2sin7∘EBsin53∘=1.2sin7∘ (M1)(A1)
Note: Award (M1) for substitution into sine formula, (A1) for correct substitution.
(EB=) 7.86 m(EB=) 7.86 mOR786 cm (7.86385… m786 cm (7.86385… mOR786.385… cm)786.385… cm) (A1) (C3)
[3 marks]
34° (A1) (C1)
[1 mark]
Units are required in parts (a) and (c).
sin34∘=height7.86385…sin34∘=height7.86385… (M1)
Note: Award (M1) for correct substitution into a trigonometric ratio.
(height=) 4.40 m(height=) 4.40 mOR440 cm (4.39741… m440 cm (4.39741… mOR439.741… cm)439.741… cm) (A1)(ft) (C2)
Note: Accept “BT” used for height. Follow through from parts (a) and (b). Use of 7.86 gives an answer of 4.39525….
[2 marks]