Solved

Math question.  pow(a,b)

Posted on 2000-05-11
6
199 Views
Last Modified: 2010-04-01
What is the easiest way to use java.lang.Math to solve the equation 10^x = 3000? Solve for x.
0
Comment
Question by:kevinhol
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3
6 Comments
 
LVL 3

Expert Comment

by:tgoetze
ID: 2802811
To solve for x, you take the log of both sides. Here log means the log base 10. This results in a solution of:
x = log(3000);

This is done via the log() method in java.lang.Math.

double x = java.lang.Math.log(3000.0);
0
 

Author Comment

by:kevinhol
ID: 2804871
Adjusted points from 50 to 100
0
 

Author Comment

by:kevinhol
ID: 2804872
Thanks tqoetze,

Although you did answer my original question, I have decided to change it to include different bases other than 10. ie 4^x = 3000. I've up'd the points and will hold them for you if you can answer.
0
MS Dynamics Made Instantly Simpler

Make Your Microsoft Dynamics Investment Count  & Drastically Decrease Training Time by Providing Intuitive Step-By-Step WalkThru Tutorials.

 
LVL 3

Expert Comment

by:tgoetze
ID: 2804944
Good thing you ask for some more details, I checked and found out that java.lang.Math.log is the natural logarithm, which is the log base e.

For convseion, the general rule is that the log base a of x is equal to the log base c of x divided by the log base c of a. This allows the conversion between bases.

To answer your original question (which I was wrong with first), you would need to do:

double x = java.lang.Math(3000.0)/java.lang.Math(10.0);

And for your next problem:

To solve 4^x = 3000. You simply do
log(3000)/log(4).
In java:

double x = java.lang.Math.log(3000.0)/java.lang.Math.log(4.0);

0
 
LVL 3

Accepted Solution

by:
tgoetze earned 100 total points
ID: 2807853
kevinhol,

Does the answer I posted make sense? Does it answer your question for you? Please let me know if you have any further questions about this.

0
 

Author Comment

by:kevinhol
ID: 2811046
Thanks, it worked well in my program.

P.S. I thought I excepted your comment as an answer last week, sorry for the delay.
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
hibernate jars 4 60
ejb entity bean example 2 38
Why is enum singleton a better approach than static factory 3 52
Coding for the first time 9 70
For beginner Java programmers or at least those new to the Eclipse IDE, the following tutorial will show some (four) ways in which you can import your Java projects to your Eclipse workbench. Introduction While learning Java can be done with…
Introduction This article is the first of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article explains our test automation goals. Then rationale is given for the tools we use to a…
Viewers learn about the “while” loop and how to utilize it correctly in Java. Additionally, viewers begin exploring how to include conditional statements within a while loop and avoid an endless loop. Define While Loop: Basic Example: Explanatio…
This tutorial explains how to use the VisualVM tool for the Java platform application. This video goes into detail on the Threads, Sampler, and Profiler tabs.

726 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question