When may it be a good idea to use scientific notation for si prefixes?

I believe SI is the international system of measurements, our metric system. You would want to use this when numbers begin to get too small, or too large. Some examples would be when calculating distances of spacial bodies such as  the distance from earth to the center of the milky way which is about 1,000,000,000,000,000,000 km  or 1*10^18. 1*10^18 is easier to write and is less confusing.

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.