6. For the unlimited population model with y > 1, check that solutions assume the form discussed in the lecture.
7. Find the general solution of the ODE y' = y2.
8. Suppose you have a cup of coffee whose temperature at the moment is 200°, and the ambient temperature is 80°. Suppose that 1 minute later the temperature of the coffee is 180°. Find the function y(t) that gives the temperature of this cup of coffee as a function of t.