7050
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2011-02-01T00:00:01
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<td>In this diagram $O$ is the centre of a unit circle. Use it to
find a trigonometrical relationship between $A$ and $2A$.</td>
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<div class="framework">
<span style="font-style: italic;">Did you
know ... ?</span>
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<br />
Trigonometrical expressions can often be derived algebraically or
geometrically. In more advanced applications the functions of
trigonometry are defined as infinite power series rather than
geometric ratios.</div>
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<mdoxml version="1.0">This image, making use of results from circle theorems, says it
all!<br></br>
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<mdo:image height="322" width="328" src="solution.jpg" alt="solution picture"></mdo:image><br></br>
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<?xml version="1.0" encoding="UTF-8"?>
<mdoxml version="1.0">This image, making use of results from circle theorems, says it
all!<br></br>
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<mdo:image height="322" width="328" src="solution.jpg" alt="solution picture"></mdo:image><br></br>
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Weekly Challenge 21: Trig identity
A weekly challenge: these are shorter problems aimed at Post-16 students or enthusiastic younger students.
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