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int n = 50000;		double sum1=0;		double sum2=0;		for(int i =1;i<=n;i++) {						sum1 = sum1 + 1.0/i;		}		System.out.printf("result 1:%7.15f\n",sum1);				for(int i=n;i>=1;i--) {						sum2 = sum2+ 1.0/i;		}		System.out.printf("result 2:%7.15f\n",sum2);		System.out.printf("The diffrence between two result is:%7.15f",(sum2-sum1));

double sum = 0;		double k =1.0;		for(int i=3;i<=99;i+=2) {						sum +=  k/i;			k+=2;		}		System.out.printf("The  Sequence sum is :%5.8f",sum);

java.util.Scanner input = new java.util.Scanner(System.in);		double sum = 0;		System.out.print("Enter number of n:");		int n =input.nextInt();				for(int i =1;i<=n;i++) {						if(i%2==0)				sum+= (-1.0)/(2*i-1);			else				sum+=1.0/(2*i-1);					}		System.out.printf("when  n= %d  PI is :%5.9f\n",n,4*sum);

java.util.Scanner input = new java.util.Scanner(System.in);		System.out.print("Enter number of n :");		int n = input.nextInt();		double item = 1;		double e =1.0;			for(int i =1;i<=n-1;i++) {						item = item/i ;						e+=item;		}		System.out.printf("The e is : %5.9f",e);

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