题目：
1：`import numpy as np
A = np.random.randint(-20, 20, size = 30 * 20).reshape(30, 20)
b = np.random.randint(-20, 20, size = 30 * 1).reshape(30, 1)
x = np.dot(np.dot(np.linalg.inv(np.dot(A.T, A)), A.T), b)
print(x)
print (“The answer is :”, np.linalg.norm(x))`
2：`import numpy as np
from scipy import optimize
def func(x):
return -((np.sin(x - 2) * 2 ) np.exp(-x ** 2))
max = -optimize.minimize_scalar(func).fun
print(max) `
3：
import numpy as np
from scipy import spatial
X = np.random.randint(-10, 10, size = 5 * 5).reshape(5, 5)
print(X)
print(spatial.distance.cdist(X, X))