pow() function in C

The pow() function in C is used to calculate the power of a number. It computes base raised to the power of exponent and returns the result as a double. This function is declared in the math.h header file.

Syntax

double pow(double base, double exponent);

Parameters

• base − The base value whose power is to be calculated
• exponent − The power value (exponent)

Return Value

Returns the value of base raised to the power of exponent as a double.

Example 1: Basic Usage

Here is a simple example demonstrating the pow() function −

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

int main() {
    double base = 5.5;
    double exponent = 4.0;
    double result;
    
    result = pow(base, exponent);
    printf("%.1f raised to the power %.1f = %.6f<br>", base, exponent, result);
    
    return 0;
}

5.5 raised to the power 4.0 = 915.062500

Example 2: Multiple Power Calculations

This example shows various power calculations using different data types −

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

int main() {
    printf("2^3 = %.0f<br>", pow(2, 3));
    printf("2.5^2 = %.2f<br>", pow(2.5, 2));
    printf("10^-2 = %.4f<br>", pow(10, -2));
    printf("4^0.5 = %.2f<br>", pow(4, 0.5));
    
    return 0;
}

2^3 = 8
2.5^2 = 6.25
10^-2 = 0.1000
4^0.5 = 2.00

Note: On some systems, you may need to link the math library using -lm flag during compilation: gcc program.c -lm

Key Points

• Both parameters are of type double, but integers are automatically promoted
• The function can handle negative exponents and fractional powers
• For square root, use pow(x, 0.5) or the dedicated sqrt() function
• May require linking with math library (-lm) on some compilers

Conclusion

The pow() function provides a convenient way to perform power calculations in C. It handles various numeric types and supports both positive and negative exponents for flexible mathematical operations.