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Thread: Need some help with this code - Asap

  1. #1
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    Default Need some help with this code - Asap

    import java.util.Scanner;
     
    public class Text1{
    	public static void main(String [] args){
     
    		Scanner input = new Scanner(System.in);
    		int answer = 1;
    		int number = 0;
    		int x;
     
    		System.out.print("Enter number: ");
    		number = input.nextInt();
     
    		System.out.print("Enter value of x: ");	
    		x = input.nextInt();
     
    		for (int i=1; i<=number;i++) 
    		if (answer += i * x){
    			System.out.println(i);
     
    		}
     
    	}
     
    }

    The task is to write a program to find the sum of a number of terms of the infinite series 1 + x + x2 + x3 + x4 + .... xn where the number of terms n to be evaluated and the value of x are input before the summation begins.

    Note: x0 = 1 AND x1 = x are known mathematical values

    What do you guys think?


  2. #2
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    Default Re: Need some help with this code - Asap

    answer = answer + i*x.

    x = 5;
    number = 10;

    answer = 1 + (1 *5)
    answer = 6 Good

    i = 2;
    answer = 6 + (2*5) = 16 Not good

    answer = 16 + (3*5) = 31 Not right (though it would work for 1 + 5 + 5^2)

    1 + 5 + 25 = 31

    i = 4;
    answer = 31 + (4*5) = 51.

    i = 5;

    answer = 51 + 25 = 76. Not Good

    i = 6

    answer = 76 + 30 = 106 Not good

    i = 7

    answer = 106 + 35 = 141 not good


    i = 8

    answer = 141 + 40 = 181 not good

    i = 9

    answer = 181 + 45 = 226 not good

    i = 10

    answer = 226 + 50 = 276 not good

    Also, what does it print out if somebody enters in 0 as the number?

  3. #3
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    Default Re: Need some help with this code - Asap

    This "if (answer += i * x)" is not correct because the result of the expression is not a boolean.

    Instead of this statement you can put "answer += Math.pow(x, i);"

  4. #4
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    Default Re: Need some help with this code - Asap

    Quote Originally Posted by Th3T3chGuy View Post
    import java.util.Scanner;
     
    public class Text1{
    	public static void main(String [] args){
     
    		Scanner input = new Scanner(System.in);
    		int answer = 1;
    		int number = 0;
    		int x;
     
    		System.out.print("Enter number: ");
    		number = input.nextInt();
     
    		System.out.print("Enter value of x: ");	
    		x = input.nextInt();
     
    		for (int i=1; i<=number;i++) 
    		if (answer += i * x){
    			System.out.println(i);
     
    		}
     
    	}
     
    }

    The task is to write a program to find the sum of a number of terms of the infinite series 1 + x + x2 + x3 + x4 + .... xn where the number of terms n to be evaluated and the value of x are input before the summation begins.

    Note: x0 = 1 AND x1 = x are known mathematical values

    What do you guys think?
    And...... ?
    What is the problem in code?
    What are the errors?
    What is the problem, you are facing?
    Be precise and get precise answers.

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