ECZ 2021 · GCE Paper 2 · Question 8 — Graphs of Functions
The graph of y = -(15)x(12 - x2) is given printed on the paper (x from about -4 to 4).
(a(i)(a)) Use the graph to solve -(15)x(12 - x2) = 1.[2]
Verified working — step 1
Draw the horizontal line y = 1 on the graph. Read the x-values where this line crosses the curve y = -(15)x(12 - x2).(a(i)(b)) Use the graph to solve -(15)x(12 - x2) = -2.[2]
Verified working — step 1
Draw the horizontal line y = -2 on the graph. Read the x-values where this line crosses the curve.(a(ii)(a)) Calculate an estimate of the area bounded by the curve and the lines y = 0, x = -3 and x = -1.[3]
Verified working — step 1
From the graph read the y-values at x = -3, -2, -1:(a(ii)(b)) Calculate an estimate of the gradient of the curve at the point (3, -1.8).[2]
Verified working — step 1
Draw a tangent to the curve at the point (3, -1.8).(b) Find the equation of the curve for which dydx= 2x - 3 where x = y = 3.[3]
Verified working — step 1
Given dydx= 2x - 3, integrate with respect to 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.
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