Answer:
B
Step-by-step explanation:
He found out how many people who play 2+ instruments are 8th graders rather than how many 8th graders play 2+ instruments.
So, the function is obviously shifted up by 1 so it rules out A and B, and we also see that the period is 4pi rather than 2pi, and using the fact that:

Now that we know our b value, we see that the correct answer would be C.
Answer:

Step-by-step explanation:
Explicit formulas are used to represent all the terms of the geometric sequence with a single formula.

a is the first term.
r is the common ratio.
r = second term ÷ first term.
3 , - 6 , 12, - 24, 48 ,........
a = 3
r = -6 ÷ 3 = -2


Check:

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