My Math Forum  

Go Back   My Math Forum > College Math Forum > Calculus

Calculus Calculus Math Forum


Reply
 
LinkBack Thread Tools Display Modes
November 3rd, 2012, 11:23 AM   #1
Newbie
 
Joined: Sep 2012

Posts: 22
Thanks: 0

Second Derivative Test

When do you use the second derivative test instead of the first derivative test when determining relative max/min?
BrianMX34 is offline  
 
November 3rd, 2012, 11:33 AM   #2
Senior Member
 
MarkFL's Avatar
 
Joined: Jul 2010
From: St. Augustine, FL., U.S.A.'s oldest city

Posts: 12,155
Thanks: 462

Math Focus: Calculus/ODEs
Re: Second Derivative Test

You can use either the first derivative test or the second derivative test to determine the nature of extrema. Which you use is often a matter of convenience, i.e., which is simpler.
MarkFL is offline  
November 3rd, 2012, 11:40 AM   #3
Newbie
 
Joined: Sep 2012

Posts: 22
Thanks: 0

Re: Second Derivative Test

That's what I thought because I used both for the same problem and got the same answer. So there's no situation where you'd have to use one over the other unless specific in the question? Excluding, when using the second derivative and getting 0 as an answer, because I know when that happens you have to use the FDT. Thank you very much!
BrianMX34 is offline  
November 3rd, 2012, 12:05 PM   #4
Senior Member
 
MarkFL's Avatar
 
Joined: Jul 2010
From: St. Augustine, FL., U.S.A.'s oldest city

Posts: 12,155
Thanks: 462

Math Focus: Calculus/ODEs
Re: Second Derivative Test

When both the first and second derivatives are zero at a point, then it is not an extremum. Sometimes it is easier to use one test over the other, and unless otherwise instructed I would use the easier of the two tests.
MarkFL is offline  
Reply

  My Math Forum > College Math Forum > Calculus

Tags
derivative, test



Search tags for this page
Click on a term to search for related topics.
Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
First Derivative Test SamFe Calculus 1 November 7th, 2013 12:04 PM
What does this mean: f' does not exist (1e derivative test) Gerrit Calculus 13 October 14th, 2013 04:33 AM
1st derivative test mathkid Calculus 5 October 6th, 2012 07:22 PM
Help with graphing second derivative test on Ti-84...... RealMadrid Calculus 1 July 19th, 2012 02:24 PM
Second Derivative Test SyNtHeSiS Algebra 5 May 26th, 2010 04:28 AM





Copyright © 2017 My Math Forum. All rights reserved.