# Science:Math Exam Resources/Courses/MATH102/December 2013/Question A 07

MATH102 December 2013
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### Question A 07

The number of sunspots (solar storms on the sun) varies with a period of roughly 11 years reaching a high of 120 and a low of 0 sunspots detected. A peak of 120 sunspots was detected in the year 2000. Which of the following trigonometric functions could be used to approximate this cycle?

(a) $N=60+120\sin \left({\frac {2\pi }{11}}(t-2000)+{\frac {\pi }{2}}\right)$ (b) $N=60+60\sin \left({\frac {11}{2\pi }}(t+2000)\right)$ (c) $N=60+60\cos \left({\frac {11}{2\pi }}(t+2000)\right)$ (d) $N=60+60\sin \left({\frac {2\pi }{11}}(t-2000)\right)$ (e) $N=60+60\cos \left({\frac {2\pi }{11}}(t-2000)\right)$ Make sure you understand the problem fully: What is the question asking you to do? Are there specific conditions or constraints that you should take note of? How will you know if your answer is correct from your work only? Can you rephrase the question in your own words in a way that makes sense to you? If you are stuck, check the hints below. Read the first one and consider it for a while. Does it give you a new idea on how to approach the problem? If so, try it! If after a while you are still stuck, go for the next hint.

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