Subtract the fraction and simplify the answer 13/15 - 1/5

Find the common denominator.
multiply 1/5 by 3 on the top and bottom.
then solve normally.
then simplify 10/ 15 you should get 2/3.

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.