Question

write the program to find the sum of first 20 terms of series: S=2/3+4/5+8/7+16/9+............

Answer 1

float sum=0.0;

for(int i=0;i<=20;i++){

float k=math.pow(2,i) / (2*i+1);

sum+=k;

System.out.print(sum);

}

this is java program in c++ as follows

#include<math.h>

float sum=0.0;

for(int i=0;i<=20;i++){

float k=pow(2,i) / (2i+1);

sum+=k;

cout<<sum;

}

Answer 2

Program code to find the sum of 1st 20 terms of the series is:

#include <bits/stdc++.h>  

using namespace std;  

 

// Function to find sum of series  upto n terms  where n=20

//double datatype used to store the sum value

double Sum(int n)  

{  

   // initializing counter by 1  

   int i = 1;  

     

   // variable to calculate result  

   double result = 0.0;  

   bool sign = true;  

     

   // while loop until nth term is not reached  

   while (n > 0)  

   {  n--;  

     // bool type variable for checking and validating  is used

              if (sign)

              {  sign = !sign;  

              result = result + (double)++i / ++i;  

               }  

                else

              {    sign = !sign;  

               result = result - (double)++i / ++i;  

               }  

   }  

return result;  

}  

   

int main()  

{   int n = 20;  

   cout << Sum(n);      

   return 0;  

}