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0606/12 May/Jun 2026, Question 1: Trig Graphs: Amplitude and Period

Cambridge IGCSE Additional Mathematics 0606 · Paper 12 (Non-calculator) · Non-calculator · 5 marks

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The question, in short

Without a calculator, sketch y = 4 cos x − 2 over −360° to 360°, then state its amplitude, its period, and the k values giving at least two solutions of 4 cos x − 2 = k.

Summarised in our own words. Use the official paper for the exact wording and any diagrams.

Part (a) · 2 marks

Draw the curve y = 4 cos x − 2 on the given axes for x from −360° to 360°.

  1. 1Maximum value 4 − 2 = 2 at x = 0°, ±360°
  2. 2Minimum value −4 − 2 = −6 at x = ±180°
  3. 3y = −2 (the centre line) at x = ±90°, ±270°
  4. 4Two full cycles between −360° and 360°

AnswerTwo full cosine cycles: maximum 2 at x = −360°, 0°, 360°; minimum −6 at x = −180° and 180°; passing through (−270, −2), (−90, −2), (90, −2), (270, −2)

Part (b) · 1 mark

State the amplitude of the function 4 cos x − 2.

  1. 1Amplitude is the coefficient of cos x: 4

Answer4

Part (c) · 1 mark

State the period of the function 4 cos x − 2.

  1. 1The period of cos x is 360°, unchanged by ×4 or −2

Answer360°

Part (d) · 1 mark

Find all k for which 4 cos x − 2 = k has two or more solutions.

  1. 1The line y = k must meet the graph at least twice
  2. 2The graph takes values from −6 to 2, and every value in this range is reached at least twice
  3. 3−6 ≤ k ≤ 2

Answer−6 ≤ k ≤ 2

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Also searched as: 0606/12/M/J/26 · 0606_s26_qp_12 · 0606 s26 12 · question 1.
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