Melons are spaced 1 meter apart in a square x-y grid. One plant is replaced by an irrigation sprayer. The sprayer covers those plants that satisfy the relationship x^2+y^2 < or equal to 20 meters, with the sprayer at (0,0). What are all the possible x coordinates of plants watered by this sprayer? What are all the possible y coordinates of plants watered by this sprayer? List the possible x-coordinates and the possible y-coordinates as separate sets, and sketch this situation. Is the relationship of x and y a function? Why?