# 2.1  Expressions
# Art Belmonte, Summer 1996
# These are the shaded gray examples which appear in Section 2.1.
> restart; f:=2*x^3 - 5*x^2 + x + 2;

                               3      2
                       f := 2 x  - 5 x  + x + 2

> factor(f);

                      (x - 1) (x - 2) (2 x + 1)

> plot(f, x=-2..3);
> vol:=Pi*h*r^2;

                                         2
                            vol := Pi h r

> x:=6;

                                x := 6

> f;

                                 260

> unassign('x'); subs(x=6, f);

                                 260

> subs(x=a+h, f);

                          3            2
                 2 (a + h)  - 5 (a + h)  + a + h + 2

> subs(r=2, h=5, vol);

                                20 Pi

>