super busy with annoying shizzle like matlab -_-...eg (what im doing at this very second)

%  x^2*sin(x)
clear all

m=input('Enter the arbitary constant, m:  ');
N=input('Enter the number of iterations, N:  ');
fun=input('Enter your fucntion, f(x)=  ','s');
fprintf('\n');
f=inline(fun,'x');

z(1)=m*((2*(-1)/(N-1))-1);
x(1)=asin(z(1));
for j=2:(N+2)
   
    a=j-1;
    %a=j;
z(j) = m*((2*(a-1)/(N-1))-1);
x(j) = asin(z(j));
end

delz=z(j)-z(j-1);

for j=2:(N+1)
    %z(j) = m*((2*(j-1)/(N-1))-1);
    %x(j) = asin(z(j));
   
    %f1(j)=f(x(j+1));
    %f2(j)=f(x(j-1));
    %f3(j)=f(x(j+2));
    %f4(j)=f(x(j));
    %f5(j)=f(x(j-2));
    gdot(j)=cos(x(j));
   
    if (j>2) || (j<(N+1))
        f2(j)=f(x(j-1));
        f1(j)=f(x(j+1));
        dfdz(j) = (f1(j)-f2(j))/(2*delz);
        dfdx(j)=(gdot(j))*(dfdz(j));
        end
       
 
        if j == 2
        f1(j)=f(x(j+1));
        f3(j)=f(x(j+2));
        f4(j)=f(x(j));
        dfdz(j)=(4*f1(j)-f3(j)-3*f4(j))/(2*delz);
        dfdx(j)=(gdot(j))*(dfdz(j));
        end
       
       
       if j == (N+1)
        f1(j)=real(f(x(j-1)));
        f5(j)=f(x(j-2));
        f4(j)=f(x(j));
        dfdz(j)=(f5(j)-4*f1(j)+3*f4(j))/(2*delz);
        dfdx(j)=(gdot(j))*(dfdz(j));
        end
end

for i=1:N
    y(i)=x(i+1);
    df(i)=dfdx(i+1);
end

plot(y,df);

table(:,1)=1:N;
table(:,2)=y;
table(:,3)=df;
fprintf('\tj\t\t x(j)\t\t df/dx\t\t \n');
for i=1:N       %shows the values of the column one row at a time
fprintf('%6.2f\t\t %6.2f\t\t %6.2f\t\n',table(i,1),table(i,2),table(i,3));
end;