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.