## Program to Plot Cosine function?

Cosine function in Mathematics: In mathematics, the trigonometric functions are also called circular functions, angle functions or goniometric functions. These functions are actual functions that relate an attitude of a right-angled triangle to ratios of two side lengths.

These functions are used in all sciences that are related to geometry, such as navigation, solid mechanics, celestial mechanics, geodesy, and many other fields. They are among the very simple periodic functions, and as such are also extensively used for reading periodic phenomena, through Fourier analysis.

The most extensively used trigonometric functions are the sine, the cosine, and the tangent.

## Cosine function in Python:

In this section, we discuss the Cosine function in python. How we can use CoSine function in python along with syntax.

cos():-  In Python, the math module contains various mathematical operations, which can be performed using the module. math.cos() function returns the cosine of the value passed as an argument.math.cos() function is from Standard math Library of Python Programming Language.

The purpose of this function is to calculate the cosine of any given number is either positive or negative. This function is not accessible directly, so we need to import the math module and then we need to call this function using math static object.

Syntax:- The syntax of cos() function in Python is:

math.cos( x )

In Python cos() function returns the cosine of x radians.The value passed in this function should be in radians. This function returns the cosine of the value passed as an argument.

But in this article, we implement the Cosine function with matplotlib and numpy. you can also be used math module when it gives results in radians. so we can implement using numpy. we discuss here how to use numpy.cos() in Python along with code and also discuss Program to Plot Cosine function? in Python programming.

numpy.cos() in Python

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

Cosine waves are periodic waves generated out of oscillations. Cosine waves are the same as a sine wave, on the other hand, the cosine wave leads sine wave by 90 degrees of the phase angle.

The cosine curve does not go through the origin. The ocean tides are an example of cosine waves. A cosine curve can be plotted using the cosine() on a numpy array and the plot() function of the pyplot module of matplotlib.

Python Code:

import numpy as np
from matplotlib import pyplot as plt
x = np.arange(
0,3*np.pi,0.01)
a =
5
b = 4
y = np.cos(a*x+b)
plt.plot(x,y)
plt.xlabel(
'x values')
plt.ylabel(
'y values')
plt.title(
'cos function')
plt.grid(
True)
plt.show()

Output:
 Program to Plot Cosine function

Summary: In this article, we discuss the cosine function in detail. first of all, we discuss sine function in mathematics, the definition of the cosine function and how actually it is used in mathematics. then we discuss sine function in Python along with the syntax of the cosine function in python.

There are two ways we used cosine() function in python. The first one is math.cosine(x) in this case we need to import the math module. the second one is numpy.cosine() using numpy and matplotlib for plotting graph of the cosine function.

In the last, we discuss the code for the Plotting the graph of the Cosine function with output. In this code first, we need to import numpy and we used numpy as np then we need to import matplotlib which is necessary to plot a graph. so we defined matplotlib as plt.

In this matplotlib.pyplot is a collection of functions that make matplotlib work like MATLAB. For every pyplot function makes some change to a figure: e.g., creates a figure, creates a plotting area in a figure, plots some lines in a plotting area, decorates the plot with labels, etc.