| Exam Board | CAIE |
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| Module | P3 (Pure Mathematics 3) |
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| Year | 2003 |
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| Session | November |
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| Topic | Trig Equations |
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3 Solve the equation
$$\cos \theta + 3 \cos 2 \theta = 2$$
giving all solutions in the interval \(0 ^ { \circ } \leqslant \theta \leqslant 180 ^ { \circ }\).