numpy.sin(x[, out]) = ufunc 'sin') : This mathematical function helps user to calculate trigonometric sine for all x(being the array elements). 
Parameters : 
 

array    : [array_like]elements are in radians. 

2pi Radians = 36o degrees

Return : 
 

An array with trigonometric sine of
x for all x i.e. array elements 

  
Code #1 : Working 
 

# Python program explaining
# sin() function

import numpy as np
import math

in_array = [0, math.pi / 2, np.pi / 3, np.pi]
print ("Input array : \n", in_array)

Sin_Values = np.sin(in_array)
print ("\nSine values : \n", Sin_Values)

Output : 
 

Input array : 
 [0, 1.5707963267948966, 1.0471975511965976, 3.141592653589793]

Sine values : 
 [  0.00000000e+00   1.00000000e+00   8.66025404e-01   1.22464680e-16]

  
Code #2 : Graphical representation 
 

# Python program showing
# Graphical representation of 
# sin() function

import numpy as np
import matplotlib.pyplot as plt

in_array = np.linspace(-np.pi, np.pi, 12)
out_array = np.sin(in_array)

print("in_array : ", in_array)
print("\nout_array : ", out_array)

# red for numpy.sin()
plt.plot(in_array, out_array, color = 'red', marker = "o")
plt.title("numpy.sin()")
plt.xlabel("X")
plt.ylabel("Y")
plt.show()

Output : 
 

in_array :  [-3.14159265 -2.57039399 -1.99919533 -1.42799666 -0.856798   -0.28559933
  0.28559933  0.856798    1.42799666  1.99919533  2.57039399  3.14159265]

out_array :  [ -1.22464680e-16  -5.40640817e-01  -9.09631995e-01  -9.89821442e-01
  -7.55749574e-01  -2.81732557e-01   2.81732557e-01   7.55749574e-01
   9.89821442e-01   9.09631995e-01   5.40640817e-01   1.22464680e-16]