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C++ Exercises: Find the sum of series 1 - X^2/2! + X^4/4!-.... upto nth term

C++ For Loop: Exercise-14 with Solution

Write a program in C++ to find the sum of series 1 - X^2/2! + X^4/4!-.... upto nth term.

Sample Solution :-

C++ Code :

#include <iostream>
#include <math.h>
using namespace std;

int main()
{
    float x, sum, term, fct, y, j, m;
    int i, n;
    y = 2;

    cout << "\n\n Find the sum of the series 1 - X^2/2! + X^4/4!-....:\n";
    cout << "---------------------------------------------------------\n";
    cout << " Input the value of X: ";
    cin >> x;
    cout << " Input the value for nth term: ";
    cin >> n;
    sum = 1;
    term = 1;
    cout << " term 1 value is: " << term << endl;
    for (i = 1; i < n; i++) 
	{
        fct = 1;
        for (j = 1; j <= y; j++) 
		{
            fct = fct * j;
        }
        term = term * (-1);
        m = pow(x, y) / fct;
        m = m * term;
        cout << " term " << i + 1 << " value is: " << m << endl;
        sum = sum + m;
        y += 2;
    }
    cout << " The sum of the above series is: " << sum << endl;
}

Sample Output:

 Find the sum of the series 1 - X^2/2! + X^4/4!-....:                  
---------------------------------------------------------              
 Input the value of X: 3                                               
 Input the value for nth term: 4                                       
 term 1 value is: 1                                                    
 term 2 value is: -4.5                                                 
 term 3 value is: 3.375                                                
 term 4 value is: -1.0125                                              
 The sum of the above series is: -1.1375

Flowchart:

Flowchart: Find the sum of series 1 - X^2/2! + X^4/4!-.... upto nth term

C++ Code Editor:

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Previous: Write a program in C++ to calculate the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (1+2+3+4+...+n).
Next: Write a program in C++ to asked user to input positive integers to process count, maximum, minimum, and average or terminate the process with -1.

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C++ Programming: Tips of the Day

What is a smart pointer and when should I use one?

This answer is rather old, and so describes what was 'good' at the time, which was smart pointers provided by the Boost library. Since C++11, the standard library has provided sufficient smart pointers types, and so you should favour the use of std::unique_ptr, std::shared_ptr and std::weak_ptr.

There was also std::auto_ptr. It was very much like a scoped pointer, except that it also had the "special" dangerous ability to be copied - which also unexpectedly transfers ownership.

It was deprecated in C++11 and removed in C++17, so you shouldn't use it.

std::auto_ptr<MyObject> p1 (new MyObject());
std::auto_ptr<MyObject> p2 = p1; // Copy and transfer ownership. 
                                 // p1 gets set to empty!
p2->DoSomething(); // Works.
p1->DoSomething(); // Oh oh. Hopefully raises some NULL pointer exception.

Ref : https://bit.ly/3mc9GHE