> By The Good Doctor# Put your name on this line
> # Fix the errors
> with(plots);# put missing command before # 
Warning, the name changecoords has been redefined


  [animate, animate3d, animatecurve, changecoords, complexplot,

        complexplot3d, conformal, contourplot, contourplot3d,

        coordplot, coordplot3d, cylinderplot, densityplot, display,

        display3d, fieldplot, fieldplot3d, gradplot, gradplot3d,

        implicitplot, implicitplot3d, inequal, listcontplot,

        listcontplot3d, listdensityplot, listplot, listplot3d,

        loglogplot, logplot, matrixplot, odeplot, pareto, pointplot,

        pointplot3d, polarplot, polygonplot, polygonplot3d,

        polyhedra_supported, polyhedraplot, replot, rootlocus,

        semilogplot, setoptions, setoptions3d, spacecurve,

        sparsematrixplot, sphereplot, surfdata, textplot, textplot3d,

        tubeplot]

> contourplot(sin(x)*sin(y),x=0..2*Pi,y=0..2*Pi);
> plot3d(x^3-3*x*y^2,x=-3..3,y=-3..3);
> plot3d(x*y,x=-3..3,y=-3..3);
> contourplot(x^2+y,x=-1..1,y=-1..1);#hard typo to find
> spacecurve([cos(t),sin(t),t],t=0..10*Pi/4);
> #pi,Pi,e,E,exp,
> pi;evalf(pi);

                                  pi


                                  pi

> Pi;evalf(Pi);evalf(Pi,50);

                                  Pi


                             3.141592654


         3.1415926535897932384626433832795028841971693993751

> e;E;evalf(e);evalf(E);

                                  e


                                  E


                                  e


                                  E

> exp(1);evalf(exp(1));evalf(exp(1),50);

                                exp(1)


                             2.718281828


         2.7182818284590452353602874713526624977572470937000

> #More errors to fix
> plot(exp(x),x=0..1);
> plot(exp(x),x=0..1);
> plot(cos(2*Pi*x),x=0..2*Pi);
> plot((4/5)*(cos(x))+x,x=0..2*Pi);
> # cute error, how was this done?
> a:=2;

                                a := 2

> a+a; #note the original answer has a 5 as an answer.

                                  5

> a;

                                  2

> # Is this an error? NO! The plots look different
> saddle1:=plot3d(x^2-y^2,x=-3..3,y=-3..3):saddle1;
> saddle2:=implicitplot3d(z=x^2-y^2,x=-3..3,y=-3..3,z=-3..3):saddle2;
> display(saddle1,saddle2);# show them together with display
> f:=x^2+y^2;

                                   2    2
                             f := x  + y

> plot3d(f,x=-1..1,y=-1..1); # no problem
> g:=x^2+y^2;

                                   2    2
                             g := x  + y

> plot3d(g,x=-1..1,y=-1..1);
> # never do f(x):=
> h(z):=z^2;

                                       2
                              h(z) := z

> h(3);

                                 h(3)

> h(x);

                                 h(x)

> # don't assign to variables you are going to use
> fp:=p^2+q^2;

                                   2    2
                            fp := p  + q

> p:=7;

                                p := 7

> plot3d(fp,p=-1..1,q=-1..1);
> p:='p';# this is undone by p:='p';

                                p := p

> solve({x+y=3,x-y=1},{x,y});

                            {y = 1, x = 2}

> solve({x+y=3,x-y=1},{x,y});

                            {y = 1, x = 2}

> plot3d(sin(x+y),x=0..2*Pi,y=0..2*Pi);
> plot3d(sin(x+y),x=0..2*Pi,y=0..2*Pi);
>