Need to have equipartition in my graph, but does not know how to do that.

Hey everyone. I'm stuck with an assigment, where I have to make a graph with equipartition, which I think is n number of points, which has the same distance between each other. At first I have to do it for n=4 and then n=20. If someone could tell me, how I have to do it, it would help.

I have a Bisection script:

function [ a,b ] = s(a,b,tol)

%finds zero of f in [a,b] with accuracy TOL

%Usage: E.g.

%format long

fa=adapquad(a,tol)/adapquad(1,tol)-0.5;

fb=adapquad(b,tol)/adapquad(1,tol)-0.5;

if fa==0

    b=a;

elseif fb==0

    a=b;

elseif fa*fb>0

    error('Inappropriate use');

else

    while b-a>tol

        m=(b+a)/2;

        fm=adapquad(m,tol)/adapquad(1,tol)-0.5;

        if fm==0

            a=m;

            b=m;

        elseif fa*fm<0

            b=m;

        else

            a=m;

            fa=fm;

        end

    end

end

and my other script with the graph:

%Problem 3

f= @(x) ((0.3+7.8*x-14.1*x.^2).^2+(0.3+1.8*x-8.1*x^.2)^2)^(1/2);

%Initialize graph

s=0:0.01:1;

x=0.5+0.3*s+3.9*s.^2-4.7*s.^3;

y=1.5+0.3*s+0.9*s.^2-2.7*s.^3;

plot(x,y)

hold all

t=zeros(4,1);

I get my graph, even though there are some small errors, but that's not the thing. I just need to have points on my graph. My teacher told me, that zeros(4,1) would do it, but it does not seams to work.