Answer to Question #14048 in C++ for shalenee

Question #14048
(Demonstrating cancellation errors) A cancellation error occurs when you are manipulating a very large number with a very small number. The large number may cancel out the smaller number. For example, the result of 100000000.0 + 0.000000001 is equal to 100000000.0. To avoid cancellation errors and obtain more accurate results, carefully select the order of computation. For example, in computing the following series, you will obtain more accurate results by computing from right to left rather than from left to right: 1+1/2+1/3+...+1/n Write a program that compares the results of the summation of the preceding series, computing from left to right and from right to left with n = 7000.
Expert's answer
#include <iostream>
using namespace std;

int main()

double leftToRight = 0, rightToLeft = 0;
int n = 7000;
<< "SUM( 1 / i), i in (1 .. 7000)" << endl;
for(int i = 1, j
= n; i <= 7000; ++i, --j)
leftToRight += 1.0 / i;

rightToLeft += 1.0 / j;
cout << "Left to right: "
<< leftToRight << endl;
cout << "Right to left: "
<< rightToLeft << endl;
return 0;

Need a fast expert's response?

Submit order

and get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!


No comments. Be first!

Leave a comment

Ask Your question

New on Blog