Susie is 4 years old and Cindy is 2 years
old. Their father, Terry, is 30 years old.
How long will it be before the sum of the
children's ages is half of his?

The reporter forgot to multiply the decimal by 100, making it 25%

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.