1. Let's begin with some ideas from calculus.
a. What is the integral (antiderivative) of the function y(t) = t2 + t?
b. Solve the equation y4 - 4y2 = 0.
c. For which values of t is the function y(t) = t3 - t positive?
d. Sketch the graph of y(t) = t2 - 1.
e. Sketch the graph of y(t) = t(2 - t).
2. Sketch the phase line for y' = 1.
3. Sketch the phase line for y' = -y.