What's the answer to this math question?

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1

<p><a href="http://i1053.photobucket.com/albums/s480/desuetudes/35.png%5B/url%5D"&gt;http://i1053.photobucket.com/albums/s480/desuetudes/35.png&lt;/a&gt;&lt;/p>

2

<p>The period of sin x is 2pi, so the period of sin (2x) is pi. Scaling the function or shifting does not alter the period/frequency. Therefore the frequency is 1/pi.</p>

3

<p>This looks like a math2 subject test question. If so, use [url="&lt;a href="http://talk.collegeconfidential.com/sat-subject-tests-preparation/“]this[/url”&gt;http://talk.collegeconfidential.com/sat-subject-tests-preparation/"]this[/url</a>] forum.</p>

4

<p>I agree with Kyrix1, trigonometry isn’t on the SAT.</p>