C Programming

Using Math.h Functions in C

As the name says, the “math.h” library or header file of the C programming language consists of functions that are used to perform mathematical calculations. These functions include “sin”, “cos”, “tan”, “pow”, “floor”, etc. These are the built-in functions of this library and they operate on the “double” data type and also return the result in the same data type. In this guide, we will learn to use some of the different functions from the “math.h” library of the C programming language.

Using Math.h Functions in C

In the examples discussed below, we will be using the three most common functions of the “math.h” library of the C programming language:

Example # 1: The Natural Log Function

In this example, we will be using the natural log function of the C programming language. The C script for this purpose is shown in the following image:

In this example, we have defined two double variables “x” and “result”. The value of the “x” variable is “3.2”. Then, we have saved the natural log of this variable to the “result” variable by using the “log” function of the “math.h” library. After that, we have printed this result on the terminal.

Then, to compile this script, we have used the command shown below. An important thing to be noted is that this time, we have also used the “-lm” flag with the compilation command. It is so because the C scripts containing the functions of the “math.h” header file are compiled this way. Otherwise, you will not be able to compile them.

$ gcc math.c –o math –lm

Then, this script was executed in the regular manner with the help of the following command:

$ ./math

The natural log of the specified number is shown in the image below:

Example # 2: The Square Root Function

Now, we will be using the square root function of the “math.h” library. The following C script explains this:

In this script, we have defined a number “x” whose square root is to be calculated. The value of this number is “16.0”. Then, we have stored the square root of this variable inside the “result” variable by using the “sqrt” function of the “math.h” library. After that, we have displayed this result on the terminal.

The square root of the specified number is shown in the image below:

Example # 3: The Power Function

Now, we will be using the power function of the “math.h” library. The C script for this purpose is shown in the following image:

In this program, we have defined two variables “x” and “y”. The “x” variable is the one whose “yth” power is to be calculated. Then, we have another variable “result” in which we have stored the “yth” power of “x” by making use of the “pow” function of the “math.h” library. Finally, we have printed the “yth” power of “x” on the terminal.

The “yth” power of the number “x” is shown in the image below:

Conclusion

In this guide, we have only discussed three of the most commonly used functions of the “math.h” library of the C programming language. This was done to show you how this library actually works.

About the author

Ayesha Sajid

Ayesha Sajid has secured a Bachelor's degree in Computer Sciences and a Master's degree in Information Security. She is a technical content writer by profession who has around four years of experience in working with Windows and different flavors of the Linux operating system. She also has a keen interest in exploring the latest technology trends.