The function v gives the volume of liquid in the tank in liters after t minutes. What is the best interpretation for the following statement? The slope of the line tangent to the graph of v at t equals seven is equal to negative three. So pause this video again and try to do what we just did with the previous example. Write out that interpretation, and make sure to get the units right. All right, so let's just remind ourselves what's going on. V is going to give us the volume as a function of time.