Last year, the Debate club had 7 members. This year there are 12 members in the club. Which of these is the
best estimate for the percent change in the number of
club members?
A. 25% increase
B. 100% decrease
C. 75% increase
D. 50% decrease

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.