Explain how to determine the following from the graph: number of times the barnacle went beneath the water level if the boat traveled a distance of 20 m number of meters of the 20 m trip that the barnacle was underwater

The surface area would be 576 because you multiply all the numbers then multiply that number by 6

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.