math - Why doesn't my C++ program calculate more digits of 'e'? -


i picked c++ programming language, , i'm trying calculate digits of 'e' calculus project @ school. i'll paste pgoram i've written below. it's based on e= lim(1+1/x)^x, x-> infinity. in program, set x=100,000. set x=1,000,000 , noticed answers somehow being subjected round-off error, instead of becoming longer in length.

program: 

#include <iostream> #include <math.h> using namespace std;  long double sum;  int main()  {      long double x=100000;     sum= (pow((1+(1/x)),(x)));     cout<<sum;   }

any tips/ advice in making print out more digits great. in advance.

on first hand long double limited in number of digits can produce, , because of how real numbers implemented won't produce exact results.

but, answer question can set cout's precision doing

cout.precision(15); cout << sum;

also see answer more explanations , details see how print double value full precision using cout?


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