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

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) $N=60+120\sin (\frac{2\pi }{11}(t-2000)+\frac{\pi }{2})$

(b) $N=60+60\sin (\frac{11}{2\pi }(t+2000))$

(c) $N=60+60\cos (\frac{11}{2\pi }(t+2000))$

(d) $N=60+60\sin (\frac{2\pi }{11}(t-2000))$

(e) $N=60+60\cos (\frac{2\pi }{11}(t-2000))$