ECZ 2018 · GCE Paper 1 — Trigonometry

Given a right-angled triangle XYZ where ∠Z is 90° and sin X = 45, find the value of cos X.

  • A. 45
  • B. 34
  • C. 35
  • D. 43

Verified working — step 1

sin X = oppositehypotenuse= 45, so the opposite side is 4 and the hypotenuse is 5. By Pythagoras the adjacent side is √(5² − 4²) = √9 = 3. Therefore cos X = adjacenthypotenuse= …

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.

Search any past-paper question

More Trigonometry questions from past papers