Aurora, burlington, and clifton are three cities. aurora is 65 miles west of burlington. clifton is due north of burlington and 97 miles away from aurora.
clyde and minnie leave aurora at the same time. clyde goes straight to clifton at a speed of 25 miles per hour. minnie goes from aurora to burlington to clifton at a speed of 30 miles per hour.

I assume what we are asked here are the number of hours it will take each of them to reach Clifton. Given that the distance from Clifton to Burlington is 65 miles and that from Clifton to Aurora is 95 miles, the distance from Burlington to Aurora, x, is calculated through the equation below,
                       97² = x² + 65²
The value of x from the equation is 72 miles. 
                Clyde:   97 miles / (25 miles / hour) = 3.88 hours
                 Minnie: (65 miles + 72 miles) / (30 miles / hour) = 4.57 hours
Therefore, Clyde reached Clifton first. 

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.