Add a function prototype for the function sumNum. # include using namespace sted; int main
(void) { float val; float amount; int n; cin >> val >> n; sumNum (amount, val, n); cout
Solution
Prototype of function :
In function concept prototype declaration is necessary in order to provide information to the
compiler about function, about return type, parameter list and function name etc.
Program :
# include<iostream .h >
using namespace std;
float sumNum(float,float, int);
/* prototype for the function sumNum it accept the sum value which is a float value and
parameter list mentioned, i.e. float,float, int */
int main (void) //main function
float amount;
int n;
cin>>val>>n; // Accept the value
sumNum(amount,val,n); // Calling function
cout<<amount<<end1;
}
void sumNum(float &sum, float x,int n); // Called function

{
int i;
sum=0.0; //Intilise the sum value to zero.
for(i=1;i<=n;i++)
{
sum=sum+i*x; // calculate the sum
}
return sum; // Here we return sum value
}