# numpy.cos() in Python

numpy.cos(x[, out]) = ufunc ‘cos’) : This mathematical function helps user to calculate trigonometric cosine for all x(being the array elements).
Parameters :

`array  : [array_like]elements are in radians. `

`2pi Radians = 360 degrees`

Return :

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

Code #1 : Working

## Python

 `# Python program explaining` `# cos() function`   `import` `numpy as np` `import` `math`   `in_array ``=` `[``0``, math.pi ``/` `2``, np.pi ``/` `3``, np.pi]` `print` `(``"Input array : \n"``, in_array)`   `cos_Values ``=` `np.cos(in_array)` `print` `(``"\nCosine values : \n"``, cos_Values)`

Output :

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

Cosine values :
[  1.00000000e+00   6.12323400e-17   5.00000000e-01  -1.00000000e+00]```

Code #2 : Graphical representation

## Python

 `# Python program showing` `# Graphical representation of ` `# cos() function`   `import` `numpy as np` `import` `matplotlib.pyplot as plt`   `in_array ``=` `np.linspace(``-``(``2``*``np.pi), ``2``*``np.pi, ``20``)` `out_array ``=` `np.cos(in_array)`   `print``(``"in_array : "``, in_array)` `print``(``"\nout_array : "``, out_array)`   `# red for numpy.cos()` `plt.plot(in_array, out_array, color ``=` `'red'``, marker ``=` `"o"``)` `plt.title(``"numpy.cos()"``)` `plt.xlabel(``"X"``)` `plt.ylabel(``"Y"``)` `plt.show()`

Output :

```in_array :  [-6.28318531 -5.62179738 -4.96040945 -4.29902153 -3.6376336  -2.97624567
-2.31485774 -1.65346982 -0.99208189 -0.33069396  0.33069396  0.99208189
1.65346982  2.31485774  2.97624567  3.6376336   4.29902153  4.96040945
5.62179738  6.28318531]

out_array :  [ 1.          0.78914051  0.24548549 -0.40169542 -0.87947375 -0.9863613
-0.67728157 -0.08257935  0.54694816  0.94581724  0.94581724  0.54694816
-0.08257935 -0.67728157 -0.9863613  -0.87947375 -0.40169542  0.24548549
0.78914051  1.        ]```

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