# C Program: Power of a Number

When $n$ is a positive integer, an integer $a$ multiplied to itself $n$ times is represented by $a^{n}$. $a$ is called the base and $n$ is known as exponent.

The result of the product is known as power.

When $n$ is a whole number,

$a^{2} = a \times a$

$a^{3} = a \times a \times a$

$a^{n} = a \times a \times a ... \times a$

When $n = 0$,

$a^{0} = 1$

In the below C program, we create a function called power() which computes the power of an entered number to some desired exponent by recursion.

				
#include <stdio.h>

long power (int, int);

int main() {
int exp, n;

printf("Number: ");
scanf("%d", &n);
printf("Exponent: ");
scanf("%d", &exp);

printf("%d^%d = %ld \n", n, exp, power(n, exp));
return 0;
}

long power (int number, int exponent) {
if (exponent) {
return (number * power(number, exponent - 1));
} else {
return 1;
}
}



We run the above program to find $3^{4}$, which gives the result as follows:

				
$./a.out Number: 3 Exponent: 4 3^4 = 81   We can also get the power of a number using the C function pow(), which takes two arguments of type double, where the first argument is the number and the second argument is the exponent. So, pow(2,3) computes$2^{3}\$ and gives 8.

The program below computes the power of a number using the pow() function.

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

int main() {
double n, exponent, result;
printf("Number: ");
scanf("%lf", &n);
printf("Exponent: ");
scanf("%lf",&exponent);

printf("%.1lf^%.1lf = %.2lf \n", n, exponent, pow(n,exponent));
return 0;
}