# Define f_r(x).
import numpy as np
from scipy.optimize import *

def f_r(x):
    return 20+x**2 - (0.1*np.cos(np.pi*2*x))
x = minimize(f_r, 1)
xstar = x.x
fstar = f_r(xstar)
# Locate `xstar` and `fstar`.