| Exam Board | OCR |
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| Module | C4 (Core Mathematics 4) |
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| Year | 2010 |
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| Session | January |
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| Topic | Standard Integrals and Reverse Chain Rule |
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3 By expressing \(\cos 2 x\) in terms of \(\cos x\), find the exact value of \(\int _ { \frac { 1 } { 4 } \pi } ^ { \frac { 1 } { 3 } \pi } \frac { \cos 2 x } { \cos ^ { 2 } x } \mathrm {~d} x\).