help me below algorithm.
it gives wrong output

e2 was wrong. 7.38.....

``````#include <cstdlib>
#include <iostream>
#include <math.h>

using namespace std;

int main(int argc, char *argv[])
{
float x, err, term_1,result=1.0;
int i=1,burcin;
float factorial;
cout << "x=";
cin >> x;
cout <<"error tolerance=";
cin >> err;
term_1=err+1;
while (term_1 > err)
{
factorial=1.0;
for (burcin=2;burcin <= i;++burcin)
factorial=factorial*burcin;
term_1=pow(x,i)/factorial;
result=result+term_1;
i++;
}
cout << "result is "<<result<<endl;

system("PAUSE");
return EXIT_SUCCESS;
}``````

## All 3 Replies

What is the equation you used in this computation? You initial 'i' but never assign a new value from user input; as a result, your factorial value is always 1.0. Again... I don't know what the equation is supposed to be...

e2 was wrong. 7.38.....

Not really; it would be something like that. 7.389056...

In `1 + x/1! + x^2/2! + X^3/3! + ..... + x^n/n! + x^(n+1)/(n+1)! + .....` ,
just as `n! == (n-1)! * n` , `x^n == x^(n-1) * n` .
We can eliminate the computation of pow() for each term.

``````double x ; std::cout << "x? " && std::cin >> x ;

double err ; std::cout << "error tolerence? " && std::cin >> err ;

double ex = 0.0 ;
double term = 1.0 ;

for( int n = 1 ; term > err ; ++n )
{
ex += term ;
term *= x / n ;
}``````

Dear friend,

your program is not correct. I could not catch the correct answer cout ex...
I found my mistake in my program... burcin++ is correct. ++ burcin was wrong
my assistant found it. thanks anyway.

Not really; it would be something like that. 7.389056...

In `1 + x/1! + x^2/2! + X^3/3! + ..... + x^n/n! + x^(n+1)/(n+1)! + .....` ,
just as `n! == (n-1)! * n` , `x^n == x^(n-1) * n` .
We can eliminate the computation of pow() for each term.

``````double x ; std::cout << "x? " && std::cin >> x ;

double err ; std::cout << "error tolerence? " && std::cin >> err ;

double ex = 0.0 ;
double term = 1.0 ;

for( int n = 1 ; term > err ; ++n )
{
ex += term ;
term *= x / n ;
}``````
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