September 17th, 2012, 08:33 AM  #1 
Newbie Joined: Sep 2012 Posts: 6 Thanks: 0  Critical point
What is the value of the xcoordinate of the critical point of f to 2 decimal places? f(x) = ln(x) + x^150 Any ideas guys? Thanks 
September 17th, 2012, 08:45 AM  #2 
Global Moderator Joined: Dec 2006 Posts: 17,912 Thanks: 1382 
The value is 1.03, but you would need to use calculus to find it, so you've posted the question in the wrong subforum.

September 17th, 2012, 08:56 AM  #3 
Senior Member Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,155 Thanks: 462 Math Focus: Calculus/ODEs  Re: Critical point
We are given: To find the critical point, differentiate and equate to zero: To approximate this root, we could use Newton's method: Using an initial guess of , we find after many iterations: 
September 17th, 2012, 09:51 AM  #4 
Newbie Joined: Sep 2012 Posts: 6 Thanks: 0  Re: Critical point
Thanks skipjack and MarkFL, I've made a typing error... it's supposed to be 140 instead 150. Any ideas what the answer will be? 
September 17th, 2012, 09:58 AM  #5 
Senior Member Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,155 Thanks: 462 Math Focus: Calculus/ODEs  Re: Critical point
Then you would have: 
September 17th, 2012, 10:05 AM  #6 
Newbie Joined: Sep 2012 Posts: 6 Thanks: 0  Re: Critical point
Wow you guys are brilliant, thanks!


Tags 
critical, point 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Question regarding a critical point formula  MFP  Calculus  6  August 21st, 2013 02:42 PM 
Drawing a line from point a,b .. coords point b unkown  Vibonacci  Algebra  5  September 17th, 2012 12:28 AM 
NonLinear First Order ODE: Critical Point Linearization  Mike86  Applied Math  2  October 9th, 2010 06:02 AM 
calculating point of line given starting point, slope  mathsiseverything  Algebra  1  March 4th, 2008 06:41 AM 
Critical point  felicia184  Algebra  0  December 31st, 1969 04:00 PM 