ECZ 2010 · O-Level Paper 2 · Question 2 — Circle Theorems
Question from ECZ 2010 · O-Level Paper 2 · Question 2
(a) Solve the equation 7 - 5x - x2 = 0, giving your answers correct to 2 decimal places.[5]
Verified working — step 1
Multiply through by -1 first: x2 + 5x - 7 = 0, so a = 1, b = 5, c = -7.(b) In the diagram below, ABC is a tangent and O is the centre of the circle. BE is the diameter, angle DEO = 25° and angle FEO = 22°. Calculate
(b(i)) angle BOD,[1]
Verified working — step 1
Angles BOD and BED both stand on arc BD.(b(ii)) angle CBD,[1]
Verified working — step 1
BC is a tangent and BD a chord.(b(iii)) angle DBF.[1]
Verified working — step 1
BE is a diameter, so angles BDE and BFE are each 90° (angle in a semicircle).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.
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