4024/11 May/Jun 2020, Question 17: Inverse Functions
Cambridge O Level Mathematics 4024 · Paper 11 (Non-calculator) · Non-calculator · 3 marks
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The question, in short
For f(x) = 5 − 4x, work out the value at x = −3 and determine the inverse function.
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Part (a) · 1 mark
Calculate f(−3) using the given function.
- 1f(−3) = 5 − 4 × (−3) = 5 + 12 = 17
Answer17
Part (b) · 2 marks
Find an expression for f⁻¹(x).
- 1y = 5 − 4x
- 24x = 5 − y
- 3x = (5 − y)/4
- 4f⁻¹(x) = (5 − x)/4
Answer(5 − x)/4
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Also searched as: 4024/11/M/J/20 · 4024_s20_qp_11 · 4024 s20 11 · question 17.
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