C program that computes the value of e^x

Algorithm

Step 1: Read 'n' and 'x'
Step 2: Let i = 0 and e = 0.0
Step 3: Repeat Step 3 to Step 5 for i <= n
Step 4: e = e + (x^i/i!)
Step 5: i = i + 1
Step 6: Print e^x :- 'e'

And the following algorithm illustrates the activities involved in computing a^b i.e., 'a to the power b':

START with parameter 'a' and 'b' (Both are of integer type)

Step 1: If b<0 then b=b*(-1) and flag=1 else flag=0
Step 2: Let i = 1 and p = 1.0
Step 3: Repeat Step 3 to Step 5 for i <= b
Step 4: p = p * a
Step 5: i = i +1
Step 6: If flag=0 then return 'p' else return '(1/p)'

STOP

#include<stdio.h>
#include<conio.h>

void main()
{
int n,x,i;
float e=0.0;
long factorial(int); // Prototype declaration
float power(int,int); // Prototype declaration

clrscr();
printf("Enter the value of \'n\': ");
scanf("%d",&n);
printf("Enter the value of \'x\': ");
scanf("%d",&x);
for(i=0;i<=n;i++)
e += power(x,i)/(float)factorial(i);
printf("e^x = %-15.7f",e);
}

// Recursive factorial() function
long factorial(int n)
{
if(n<0)
return 0;
else if(n==0||n==1)
return((long)(1));
else
return((long)(n*factorial(n-1)));
}

// The power() function
float power(int a,int b)
{
int i,flag;
float p=1.0;
if(b<0)
b*=-1,flag=1;
else
flag=0;
for(i=1;i<=b;i++)
p *= a;
if(flag==0)
return p;
else
return (1/p);
}

OUTPUT :

Enter the value of 'n': 7
Enter the value of 'x': 5
e^x = 128.6190491

Download source code here

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