A homeowner mows the lawn every Wednesday afternoon. Sketch a rough graph of the height of the grass as a function of time over the course of a four-week period.
The height of the grass is always the same height on each day. The height increases linearly starting
from a minimum on Wednesday, and returning to that minimum the next Wednesday.
okay, We're going to draw a simple graph that represents the height of the grass, and the grass is cut every Wednesday over the course of a four week period. And, of course, there are a lot of things that could change in different amounts of rain and sun and fertilizer. But we're just going to ignore all of those periphery details that we don't know and just imagine that the grass is growing at a steady rate all week until it's cut on Wednesday. And then it's growing at the steady rate again until it's cut the next Wednesday and so on and so on just comes back down suddenly to that cut length every Wednesday.