def bissection(f,a,b,maxiter=100):
    xv = np.zeros(maxiter)
    k = 0
    while k < maxiter:
        x = (a+b)/2
        xv[k] = x
        if (f(x)*f(a))<0:
            b = x
        else:
            a = x
        k += 1
    return xv