Math Help Forum

Math Help Forum Feed Site Feed

Go Back   Math Help Forum > University Math Help > Calculus
Reply
 
Thread Tools Display Modes
  #1  
Old March 23rd, 2009, 06:39 AM
Member
 
Join Date: Nov 2008
Posts: 171
Country:
Thanks: 50
Thanked 1 Time in 1 Post
champrock is on a distinguished road
Default kth derivative

Let f(x)={x^n(1-x)^n}/n!. Then for any integer k>0, the kth derivatives f^(k)(0) and f^(k)(1)
A. are both 0 B. are both rational numbers but not necessarily integers
C. are both integers D. do not satisfy any of the foregoing properties

i was getting A as the answer but that is not right..
Reply With Quote
Advertisement
 
  #2  
Old March 23rd, 2009, 06:51 AM
MHF Contributor
 
Join Date: Mar 2007
Posts: 1,210
Country:
Thanks: 124
Thanked 362 Times in 336 Posts
stapel is just really nicestapel is just really nicestapel is just really nicestapel is just really nicestapel is just really nice
Talking

Quote:
Originally Posted by champrock View Post
i was getting A as the answer but that is not right..
How did you arrive at your answer? What were your steps and reasoning?

Please be complete. Thank you!
Reply With Quote
  #3  
Old March 23rd, 2009, 07:09 AM
Member
 
Join Date: Nov 2008
Posts: 171
Country:
Thanks: 50
Thanked 1 Time in 1 Post
champrock is on a distinguished road
Default

I just differentiated the function once and than twice and had put x=0, 1. The method I employed was more like a hit and trial method. It would be great if you could give a more systematic approach to the question.
Reply With Quote
  #4  
Old March 23rd, 2009, 07:48 AM
MHF Contributor
 
Join Date: Mar 2007
Posts: 1,210
Country:
Thanks: 124
Thanked 362 Times in 336 Posts
stapel is just really nicestapel is just really nicestapel is just really nicestapel is just really nicestapel is just really nice
Talking

You could try finding more than just the first two derivatives... (Patterns sometimes take a while to "see".)
Reply With Quote
  #5  
Old March 24th, 2009, 03:09 AM
Member
 
Join Date: Nov 2008
Posts: 171
Country:
Thanks: 50
Thanked 1 Time in 1 Post
champrock is on a distinguished road
Default

i did, but i was getting 0 only as the answer. Kindly help!
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off
Forum Jump


All times are GMT -7. The time now is 09:11 PM.


Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2010, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.2.0 ©2008, Crawlability, Inc.
©2005 - 2009 Math Help Forum


Math Help Forum is a community of maths forums with an emphasis on maths help in all levels of mathematics.
Register to post your math questions or just hang out and try some of our math games or visit the arcade.