def f(x):
f = zeros(len(x))
f[0] = sin(x[0]) + x[1]**2 + log(x[2]) - 7.0
f[1] = 3.0*x[0] + 2.0**x[1] - x[2]**3 + 1.0
f[2] = x[0] + x[1] + x[2] -5.0