User Name Remember Me? Password

 Math Software Math Software - Mathematica, Matlab, Calculators, Graphing Software

 March 3rd, 2017, 05:50 AM #1 Newbie   Joined: Dec 2016 From: Netherlands Posts: 15 Thanks: 0 java programming incorrect answer i have to write a program that gives the summation of 1/i for any given i. i came up with the following program but for some reason it always provides the answer 1.0, can someone tell me what is wrong here? import java.util.Scanner; class Series{ Scanner sc = new Scanner(System.in); double series(int i){ if (i==1) return 1; else return 1/(i*i) + series(i-1); } public void demo(){ int i; System.out.println("Provide a number to compute the series for"); i = sc.nextInt(); System.out.println("series of " + i + " is " + series(i)); } public static void main(String[] args) { new Series().demo(); } } March 3rd, 2017, 06:33 AM   #2
Math Team

Joined: Oct 2011
From: Ottawa Ontario, Canada

Posts: 14,597
Thanks: 1038

Quote:
 Originally Posted by MathAboveMeth i have to write a program that gives the summation of 1/i for any given i.
Huh?
If i = 2, what d'hell is "summed"?
Please provide an example.
Your post is "obscure"...or do I need another coffee?  March 3rd, 2017, 06:53 AM #3 Newbie   Joined: Feb 2017 From: Netherlands Posts: 8 Thanks: 2 Math Focus: Trigonometry and complex numbers Assuming $\displaystyle i$ is a variable and not the imaginary unit: $\displaystyle \sum_{i=0}^\infty \frac{\alpha}i = \infty \thinspace \text{if} \thinspace \alpha\ne{0} \thinspace \wedge \thinspace i\ne{0}$ This can be proven with the harmonic series test. So what do you mean exactly? If you mean just $\displaystyle \frac{1}i$ you can use $\displaystyle i^{-1}$ March 3rd, 2017, 09:25 AM #4 Senior Member   Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,211 Thanks: 521 Math Focus: Calculus/ODEs I believe the OP's program is supposed to find: $\displaystyle S_i=\sum_{k=1}^{i}\left(\frac{1}{k}\right)$ It looks to me though, the algorithm coded would provide: $\displaystyle S_i=\sum_{k=1}^{i}\left(\frac{1}{k^2}\right)$ However, I'm not a Java programmer.  March 3rd, 2017, 09:46 AM #5 Member   Joined: Jan 2016 From: Athens, OH Posts: 93 Thanks: 48 Your only error is in method series. You said i is an int, so 1/i*i is 0 for any i>1! So just change 1/i*i to 1.0/i*i. By the way I am surprised that your program runs as given. I thought main had to be within a public class? Thanks from MarkFL Tags answer, incorrect, java, programming Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Similar Threads Thread Thread Starter Forum Replies Last Post mitch08 Computer Science 2 November 28th, 2015 05:51 AM CherryPi Calculus 56 February 2nd, 2012 01:13 AM duz Number Theory 7 February 9th, 2010 05:06 PM bob.dob Algebra 1 October 29th, 2008 12:50 PM conjecture Calculus 3 July 16th, 2008 05:12 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top

Copyright © 2019 My Math Forum. All rights reserved.      