# Write a NumPy program to create a vector with values from 0 to 20 and change the sign of the numbers in the range from 9 to 15.  
 import numpy as np
x = np.arange(21)
print("Original vector:")
print(x)
print("After changing the sign of the numbers in the range from 9 to 15:")
x[(x >= 9) & (x <= 15)] *= -1
print(x)
