ECZ 2018 · GCE Paper 2 · Question 8 — Trigonometry

Three villages A, B and C are connected by straight paths: AB = 15km, angle ABC = 79° and angle ACB = 40°.

(a(i)) Calculate the distance AC.[4]

Verified working — step 1

Angle A = 180° - 79° - 40° = 61°

(a(ii)) Calculate the area of triangle ABC.[2]

Verified working — step 1

Area = 12× AB × AC × sin A

(a(iii)) Calculate the shortest distance from B to AC.[2]

Verified working — step 1

Let h = shortest distance from B to AC.

(b) Solve the equation cos θ = 0.937 for 0° ≤ θ ≤ 360°.[2]

Verified working — step 1

cos θ = 0.937

(c) Sketch the graph of y = sin θ for 0° ≤ θ ≤ 360°.[2]

Verified working — step 1

Plot y = sin θ for θ = 0° to 360° using key values:

The full step-by-step working and final answer are included with Premium — checked against ECZ marking standards.

Original examination question © Examinations Council of Zambia. Worked solution and commentary © G12 Titan — not to be reproduced without permission.

Have a different question?

Search it — if it is from a past paper or a school mock, chances are we have it worked out, or one that uses the same method.