0580/41 Oct/Nov 2025, Question 28: Functions and inverse functions
Cambridge IGCSE Mathematics 0580 · Paper 41 (Extended) · Calculator · 3 marks
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The question, in short
f(x) = 7^(x − 4). Find x when f(x) = 1, and when f⁻¹(x) = 1.
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Part (a) · 1 mark
Find x when f(x) = 1.
- 17^(x − 4) = 1 = 7⁰
- 2x − 4 = 0, so x = 4
Answer4
Part (b) · 2 marks
Find x when f⁻¹(x) = 1.
- 1f⁻¹(x) = 1 means x = f(1)
- 2x = 7^(1 − 4) = 7⁻³ = 1/343
Answer1/343
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Also searched as: 0580/41/O/N/25 · 0580_w25_qp_41 · 0580 w25 41 · question 28.
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