| Exam Board | CAIE |
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| Module | P3 (Pure Mathematics 3) |
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| Year | 2011 |
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| Session | November |
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| Topic | Exponential Functions |
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1 Using the substitution \(u = \mathrm { e } ^ { x }\), or otherwise, solve the equation
$$\mathrm { e } ^ { x } = 1 + 6 \mathrm { e } ^ { - x }$$
giving your answer correct to 3 significant figures.