Basics of Common Math Functions in C Programming
Not everyone is going to employ their C language programming skills to help pilot a rocket safely across space and into orbit around Titan. No, it’s more likely that you’ll attempt something far more downtoearth. Either way, the work will most likely be done by employing math functions.
Function  #include  What It Does 

sqrt()  math.h  Calculates the square root of a floatingpoint value 
pow()  math.h  Returns the result of a floatingpoint value raised to a certain power 
abs()  stdlib.h  Returns the absolute value (positive value) of an integer 
floor()  math.h  Rounds up a floatingpoint value to the next whole number (nonfractional) value 
ceil()  math.h  Rounds down a floatingpoint value to the next whole number 
All the functions listed, save for the abs() function, deal with floatingpoint values. The abs() function works only with integers.
You can look up function references in the man pages, accessed via Code::Blocks or found online or at the command prompt in a Unix terminal window.
Math Mania Mangled is littered with a smattering of math functions. The compiler enjoys seeing these functions, as long as you remember to include the math.h header file at Line 2.
MATH MANIA MANGLED
#include <stdio.h> #include <math.h> int main() { float result,value; printf("Input a float value: "); scanf("%f",&value); result = sqrt(value); printf("The square root of %.2f is %.2fn",
value,result); result = pow(value,3); printf("%.2f to the 3rd power is %.2fn",
value,result); result = floor(value); printf("The floor of %.2f is %.2fn",
value,result); result = ceil(value); printf("And the ceiling of %.2f is %.2fn",
value,result); return(0); }
Exercise 1: Create a new project using the source code from Math Mania Mangled. Be aware that the printf() functions in the Listing were wrapped so that they’re split between two lines; you don’t need to wrap them in your source code. Build the project. Run it and try various values as input to peruse the results.
Exercise 2: Write a program that displays the powers of 2, showing all values from 2^{0} through 2^{10}. These are the Holy Numbers of Computing.

The math functions listed are only a small sampling of the variety available.

Generally speaking, if your code requires some sort of mathematical operation, check the C library documentation, the man pages, to see whether that specific function exists.

On a Unix system, type man 3 math to see a list of the C library’s math functions.

The ceil() function is pronounced “seal.” It’s from the word ceiling, which is a play on the floor() function.