1.
Develop a C program that computes X raised to the power n, X^n, recursively. In a nut shell,
input: X is a real number and n is an integer.
Program output: X is raised to the power n. Should alert the user if a negative exponent is
entered, to enter positive ONLY
Solution
/* C Code to determine computes X raised to the power n using recursive function */
#include <stdio.h>
// recursive power function
double power(double base,int exponent)
{
if(exponent == 0) return 1;
if ( exponent!=1 )
// multiply base exponenet times recursively
return (base*power(base,exponent-1));
}
int main()
{
double X;
int n;
// taking input base and exponent
printf("Enter base number(real number): ");
scanf("%lf",&X);
printf("Enter exponent(positive integer): ");
scanf("%d",&n);
// checking if exponenet is negative
// the take input again
while(n < 0)
{

2.
printf(" Invalid input ");
printf("Enter positive exponent ONLY ");
printf("Enter exponent: ");
scanf("%d",&n);
}
// calling the power function
printf("%lf^%d = %lf ", X, n, power(X, n));
return 0;
}
/*
Output:
Enter base number(real number): 3
Enter exponent(positive integer): 3
3.000000^3 = 27.000000
Enter base number(real number): 10
Enter exponent(positive integer): 2
10.000000^2 = 100.000000
Enter base number(real number): 10.1
Enter exponent(positive integer): 0
10.100000^0 = 1.000000
Enter base number(real number): 101.2
Enter exponent(positive integer): 2
101.200000^2 = 10241.440000
Enter base number(real number): 10.5
Enter exponent(positive integer): -2
Invalid input
Enter positive exponent ONLY
Enter exponent: -2
Invalid input
Enter positive exponent ONLY
Enter exponent: 0
10.500000^0 = 1.000000

3.
*/