MapleQuotientGraph.mws

>    with(plots):

Warning, the name changecoords has been redefined

>    f:=(x^4+x^3-7*x^2-x+6)/(x^2-16);

f := (x^4+x^3-7*x^2-x+6)/(x^2-16)

>    fprime:=diff(f,x);

fprime := (4*x^3+3*x^2-14*x-1)/(x^2-16)-2*(x^4+x^3-7*x^2-x+6)/(x^2-16)^2*x

>    Q:=quo(x^4+x^3-7*x^2-x+6,x^2-16,x);

Q := x^2+x+9

>    fGraph:=plot(f,x=-10..10,y=-100..100,thickness=2,discont=true):

>    Qgraph:=plot(x^2+x+9,x=-10..10,y=-100..100,thickness=2,color=blue):

>    VertAsym1:=implicitplot(x=-4,x=-10..10,y=-100..100,thickness=2,color=blue):

>    VertAsym2:=implicitplot(x=4,x=-10..10,y=-100..100,thickness=2,color=blue):

The function is graphed below in red along with the vertical asymptotes in blue and the "asymptotic parabola" in blue.

>    display(fGraph,Qgraph,VertAsym1,VertAsym2);

[Maple Plot]

>    display(fGraph);

[Maple Plot]

Notice that if we do not set "discont=true" Maple attempts to connect points on each side of a vertical asymptote.  The result is to draw nearly vertical lines that appear to be part

of the graph of the function.

>    fGraph2:=plot(f,x=-10..10,y=-100..100,thickness=2):

>    display(fGraph2);

[Maple Plot]

>    fsolve({fprime},{x},-6..-4);

{x = -5.088511437}

>    eval(f,x=-5.088511437);

37.25139071

>    fsolve({fprime},{x},-4..-2);

{x = -2.412333637}

>    eval(f,x=-2.412333637);

1.227474879

>    fsolve({fprime},{x},-1..1);

{x = -.7436981272e-1}

>    eval(f,x=-.7436981272e-1);

-.3773349988

>    fsolve({fprime},{x},1..2);

{x = 1.600749930}

>    eval(f,x=1.600749930);

.2135719706

>    fsolve({fprime},{x},4..6);

{x = 5.474464957}

>    eval(f,x=5.474464957);

61.05989744

Let's look at a "blow-up" of the graph around some of the critical points.

>    plot(f,x=-3..3,y=-3..3,thickness=2);

[Maple Plot]

>