ECZ 2024 · GCE Paper 2 · Question 10 — Graphs of Functions

Question from ECZ 2024 · GCE Paper 2 · Question 10

(a) Answer this part of the question on a sheet of graph paper. The values of x and y are connected by the equation y = -x3 + x2 + 6x. Some corresponding values of x and y are given in the table below. x-3-2-101234y180-40680q

(a(i)) Calculate the value of q.[1]

Verified working — step 1

q is the curve's y-value at x = 4:

(a(ii)) Using a scale of 2 cm to represent 1 unit on the x-axis for -3 ≤ x ≤ 4 and 2 cm to represent 10 units on the y-axis for -30 ≤ y ≤ 20, draw the graph of y = -x3 + x2 + 6x.[3]

Verified working — step 1

Plot: (-3, 18), (-2, 0), (-1, -4), (0,…

(a(iii)) Use your graph to

(a(iii)(a)) solve the equation -x3 + x2 + 5x = 4 - x,[3]

Verified working — step 1

Add x to both sides so the left matches the drawn curve:

(a(iii)(b)) estimate the gradient of the curve at the point where x = 1.[2]

Verified working — step 1

At x = 1 the curve passes through (1, 6).

(b) Find the equation of the normal to the curve y = x2 + x + 2 at the point (1, 4).[3]

Verified working — step 1

dydx = 2x + 1; at x = 1 the tangent gradient is 3.

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 Graphs of Functions questions from past papers