How to use Pre-defined mathematical function in C language?

In C programming, pre-defined mathematical functions are available in the math.h header file. These functions provide various mathematical operations like power, square root, trigonometric calculations, logarithms, and more. They help perform complex mathematical calculations easily without implementing the logic from scratch.

Syntax

#include <math.h>
double function_name(double argument);

Common Mathematical Functions

Here are some commonly used mathematical functions −

Example 1: Finding Cube Root Using pow() Function

This example demonstrates how to find the cube root of a number using the pow() function −

#include <stdio.h>
#include <math.h>

int main() {
    double number, result;
    printf("Enter a number: ");
    scanf("%lf", &number);
    
    result = pow(number, 1.0/3.0);
    printf("Cube root of %.2lf is: %.2lf
", number, result);
    
    return 0;
}

Enter a number: 27
Cube root of 27.00 is: 3.00

Example 2: Using Ceiling Function

This example shows how to use the ceil() function to round numbers up to the nearest integer −

#include <stdio.h>
#include <math.h>

int main() {
    float num1, num2, num3;
    printf("Enter 3 numbers: ");
    scanf("%f %f %f", &num1, &num2, &num3);
    
    printf("Ceiling of %.1f = %.0f
", num1, ceil(num1));
    printf("Ceiling of %.1f = %.0f
", num2, ceil(num2));
    printf("Ceiling of %.1f = %.0f
", num3, ceil(num3));
    
    return 0;
}

Enter 3 numbers: 3.7 -4.2 -6.7
Ceiling of 3.7 = 4
Ceiling of -4.2 = -4
Ceiling of -6.7 = -6

Key Points

• Always include #include <math.h> to use mathematical functions.
• Most mathematical functions work with double data type for precision.
• When compiling, you may need to link the math library using -lm flag in some systems.
• Mathematical functions return double values even when input is integer.

Conclusion

Pre-defined mathematical functions in C provide efficient solutions for complex calculations. By including math.h, you can easily perform operations like power, roots, and rounding without implementing custom algorithms.