ECZ 2018 · GCE Paper 1 — Computer and Calculator
In triangle XYZ, the side opposite angle X is x = YZ, the side opposite Y is y = XZ, and the side opposite Z is z = XY. A flow chart computes cos X: Begin → [input] → [process] → Output cos X → End. Which statements correctly complete the input and process boxes?
- A. Enter x, y, z; cos X = y² + z² + x²2yz
- B. Enter x, y, z; cos X = y² + z² − x²2yz
- C. Enter x, y, z; cos X = x² + z² − y²2xz
- D. Enter y, z; cos X = y² + z² − x²yz
Verified working — step 1
To compute cos X you need all three sides, so the input box reads “Enter x, y, z”. The cosine rule rearranged for the angle gives cos X = …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