An echo sounder is a device used to determine the depth of water by measuring the time is takes a sound produced just below the water surface t return , or echo , from the depth of water reading on the eco sounder r and the actual depth of the water w. Write two absolute value expressions equivalent to the accuracy of an echo sounder.

D. i think it is the savings

B. because the 7 represents "seven times", x represents "a number", 12 represents "plus twelve", and -4 represents "minus four"

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.