%initiation values
accuracy = abs(xr - xl);
tolerance = 1e-8;
xl = -1;
xr = 1;
funct = (6425*x.^8 - 12012*x.^6 + 6930*x.^4 - 1260*x.^2 + 35)/128;
%call the bisect function
x = bisect(funct, xl, xr, accuracy, tolerance);


function root = bisect(f, xl, xr, accuracy, tolerance)


%start with midpoint
xmid = (xl + xr)/2;
i = 0;

    while (accuracy > tolerance)
        i = i + 1;
        %if we found the root
        if f(xmid) < tolerance
            root = (xl + xr)/2;
        else
            %check which side the root is on
            if f(xl)*f(xmid) < 0
                xr = xmid;
            else
                xl = xmid;
                accuracy = abs(xr - xl);
            end
        end
    end
print root
end