Need homework help

[vishalonne]

Hello

I have 4 problems to solve out of 4 I solved 3 but problem mention below is painfull, I am not able to find how I will interchange the '+' '-' operator. I need some code. I am using Turbo C++

Write a C++ function having two value parameters X and M with result type float to find sum of series given:
1-X+1/2!X2 – 1/3!X3+1/4!X4+…..+ 1/M!XM

Thank you.

[ddanbe]

Raise the number -1 to a power, say n what will the outcome be when n is even? What if n is uneven? This tip should help.

[Ancient Dragon]

One way might be to use the % (mod) operator in the loop (function Calculate returns the result of the calculation 1/M!XM

int M = 5; // some value
int Result = 1 - X;
for(int i = 1; i <= M; i++)
{
    if( (i%2) == 0)
       Result += Calculate(i);
    else
       Result -= Calculate(i);
}

[vishalonne]

@Ancient Dragon
I tried your piece of code in my program.

Can you take a little botheration to check my code and verify it whether it is Correct or not

[vishalonne]

@ddanbe
I tried your piece of code in my program.

Can you take a little botheration to check my code and verify it whether it is Correct or not

[ddanbe]

Willing to do so, but where is your code?

[vishalonne]

@ddanbe
Sorry I am missed to give the code
here it is

#include<iostream.h>
#include<conio.h>
#include<math.h>
float Calculate(int,int);
void main()
{
    float X;
    int M;
    clrscr();
    cout<<"Enter the limit of series: ";
    cin>>M;
    cout<<"Enter value for X: ";
    cin>>X;
    float Result = 1 - X;
    for(int i = 1; i <= M; i++)
    {
     if( (i%2) == 0)
        Result +=Calculate(i,X);
     else
        Result -=Calculate(i,X);
    }
    cout<<"Sum "<<Result;
    getch();
}
float Calculate(int i,int X)
{
   float s,power;
   double fact=1.0;
   for(int j=1;j<=i;++j)
   {
     fact*=j;
     power=pow(X,i);
   }
   s=(float)1/fact*power;
   return s;
}

[Ancient Dragon]

when you run your program does it produce correct results?