My Math Forum  

Go Back   My Math Forum > College Math Forum > Applied Math

Applied Math Applied Math Forum


Reply
 
LinkBack Thread Tools Display Modes
September 18th, 2013, 06:11 AM   #1
Senior Member
 
Joined: Apr 2013
From: Ramallah, Palestine

Posts: 349
Thanks: 0

How do I minimize the expression?

how do i minimize this expression? factor out a z?

xy!z + x!yz + x!y!z
Shamieh is offline  
 
September 18th, 2013, 01:59 PM   #2
Global Moderator
 
Joined: May 2007

Posts: 6,378
Thanks: 542

Re: How do I minimize the expression?

Quote:
Originally Posted by Shamieh
how do i minimize this expression? factor out a z?

xy!z + x!yz + x!y!z
What conditions do you have on x,y,z? You can make them all 0.
mathman is offline  
September 18th, 2013, 03:06 PM   #3
Global Moderator
 
CRGreathouse's Avatar
 
Joined: Nov 2006
From: UTC -5

Posts: 16,046
Thanks: 937

Math Focus: Number theory, computational mathematics, combinatorics, FOM, symbolic logic, TCS, algorithms
Re: How do I minimize the expression?

Quote:
Originally Posted by mathman
What conditions do you have on x,y,z? You can make them all 0.
I think -- but I'm not sure -- that the task is to simplify the expression, rather than choose values for x, y, and z.
CRGreathouse is offline  
September 19th, 2013, 07:14 AM   #4
Math Team
 
Joined: Sep 2007

Posts: 2,409
Thanks: 6

Re: How do I minimize the expression?

Quote:
Originally Posted by Shamieh
how do i minimize this expression? factor out a z?

xy!z + x!yz + x!y!z
What does the '!' mean? The factorial? Are x and y assumed to be integers? What about z?

Yes, you can factor out z to get z(xy!+x!y+ x!y!). I don't see anything more to be done to make that simpler.

(You could also factor out x and y to get xyz((y-1)!+ (x-1)!+ (x-1)!(y- 1)!) but I wouldn't call that "simpler".)
HallsofIvy is offline  
September 19th, 2013, 10:21 AM   #5
Senior Member
 
MarkFL's Avatar
 
Joined: Jul 2010
From: St. Augustine, FL., U.S.A.'s oldest city

Posts: 12,155
Thanks: 463

Math Focus: Calculus/ODEs
Re: How do I minimize the expression?

Quote:
Originally Posted by Shamieh
how do i minimize this expression? factor out a z?

xy!z + x!yz + x!y!z
As you can see, folks are trying to decide what you mean here. I suggest posting the context of the problem as well (Truth Tables, Canonical Sums and Minimizing the Canonical Sum).
MarkFL is offline  
Reply

  My Math Forum > College Math Forum > Applied Math

Tags
expression, minimize



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Selecting a subset from a set to minimize a quantity ShNaYkHs Applied Math 0 November 29th, 2013 01:02 PM
Minimize the function in the basis of CNF in two ways Eug3ne Applied Math 0 January 13th, 2012 06:17 PM
Minimize the infinity norm of a matrix ricconna Linear Algebra 0 August 23rd, 2011 09:55 PM
Local minimize BakyX Algebra 1 November 17th, 2010 11:44 AM
Minimize function johnnib Applied Math 3 April 9th, 2009 07:12 AM





Copyright © 2017 My Math Forum. All rights reserved.