0606/22 May/Jun 2025, Question 3: Functions: One-One, Inverses and Restricted Domains
Cambridge IGCSE Additional Mathematics 0606 · Paper 22 (Calculator) · Calculator · 4 marks
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The question, in short
Using f(x) = 3x/(x + 4) for x > 0 and g(x) = √(x + 2) for x > −2, find the x-value satisfying fg(x) = 1.
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Solution · 4 marks
- 1fg(x) = 3√(x + 2)/(√(x + 2) + 4)
- 23√(x + 2) = √(x + 2) + 4
- 32√(x + 2) = 4, so √(x + 2) = 2
- 4x + 2 = 4, x = 2
Answerx = 2
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Also searched as: 0606/22/M/J/25 · 0606_s25_qp_22 · 0606 s25 22 · question 3.
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