Calculus Common Sense
Two young children are digging a hole in a sandbox. They dig in the area confined by the lines y = x, y = -x and y = -5 and are able to increase the depth of the hole at a rate of dh/dt = 1 meter every 30 minutes. Keeping in mind that dh/dt is a negative, write a function f(t) that defines the amount of dirt in the hole at any given moment.