Aquileo | Power Function in C

The pow() function in C is used to calculate the value of a number raised to a given power. It is defined in the <math.h> header file and returns the result of baseexponent.

It is commonly used for mathematical and scientific calculations.
It supports double, float, and long double data types.

#include <stdio.h>
// Include math.h for the pow() function
#include <math.h>  

int main() {
    double base = 5, exponent = 3, result;

    // Calculate the result of base 
    //  raised to the power of exponent
    result = pow(base, exponent);

    // Output the result
    printf("%.0f raised to the power of %.0f is %.0f\n", base, exponent, result);

    return 0;
}

Output

5 raised to the power of 3 is 125

Note: To use the pow() function, include the <math.h> header file in the program.

Syntax

double pow(double base, double exponent);

Parameters:

base: Number to be raised
exponent: Power value

Return Value:

The function returns the value of, baseexponent

Example: Using pow() with Double Values

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

int main()
{
    //taking double as input
    double x = 6.176, y = 4.832;

    printf("%f raised to power of %f is %f\n", x, y, pow(x, y));
    
    //taking float as input
    float a = 3.14, b = 2.58;

    printf("%f raised to power of %f is %f\n", a, b, pow(a, b));
    
    //taking long double as input
    long double p = 2.1591, q = 2.8642;

    printf("%Lf raised to power of %Lf is %f\n", p, q, pow(p, q));
    

    return 0;
}

Output

6.176 raised to power of 4.832 is 6617.56
3.14 raised to power of 2.58 is 19.146
2.1591 raised to power of 2.8642 is 9.06617

Example: Using pow() with Float Values

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

int main() {

    float a = 3.14, b = 2.58;

    printf("%f raised to power of %f is %f",
           a, b, pow(a, b));

    return 0;
}

Output

3.140000 raised to power of 2.580000 is 19.146019

pow() Function with Integers

The pow() function returns a double value, so integer results may sometimes produce inaccurate outputs due to floating-point precision issues.

For example:

pow(5, 2)
may internally store: 24.9999999
instead of: 25

When converted directly to int, it may produce incorrect results on some compilers.

Correct Way to Use pow() with Integers

We can solve this issue using:

Typecasting with 1e-9
round() function

Example: pow() with Integers

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

int main()
{
    int a, b;

    // Using typecasting for
    // integer result
    a = (int)(pow(5, 2) + 1e-9);
    b = round(pow(5,2));
    printf("%d \n%d", a, b);

    return 0;
}

Try It Yourself

Output

25 
25

Time Complexity: O(log(n))
Auxiliary Space: O(1)

Power Function in C

Syntax

pow() Function with Integers

Correct Way to Use pow() with Integers

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