Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

if y'=(1/x') therefore x'=(1/y')   so d(5)y/dx(5) =y''''' and x'''''=1/[d(5)y/dx(5)]=dx(5)/d(5)y

Posted on 2016-09-06
9
Medium Priority
?
55 Views
Last Modified: 2016-10-10
I had this question after viewing Is (dx²)/(d²y) is acceptable as second derivative?.
0
Comment
Question by:John Sebastian
[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
  • 5
  • 3
9 Comments
 
LVL 27

Expert Comment

by:aburr
ID: 41786375
Your equation has difficulties with the meaning that you attach to it. Consider your premise

if y'=(1/x')

It is wrong. Try it on a simple function like y = x^3. It will not work.     (If you have trouble, ask)
0
 

Author Comment

by:John Sebastian
ID: 41789244
y=x^3

y'=3x²

1=3x²x'   →x'=1/3x²

y'=1/x' is correct
0
 
LVL 27

Expert Comment

by:aburr
ID: 41789959
1=3x²x'  
I have a hard time figuring out how you got this relationship.
0
Independent Software Vendors: 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!

 

Author Comment

by:John Sebastian
ID: 41790326
Dx/dy
0
 
LVL 27

Expert Comment

by:aburr
ID: 41790525
but if y = x^3      x = y^(1/3)
dx/dy is then =
                                (1/3)y^(-2/3)      not 3x²x'
0
 

Author Comment

by:John Sebastian
ID: 41790782
1=3x²x'→x'=1/3x²→x'=1/3(y⅓
→x'=1/3(y⅔)
Note that x=y^(1/3)
Therefore they have the same answer... Am i wrong?
0
 
LVL 27

Expert Comment

by:aburr
ID: 41791935
"Am i wrong?"   no    I am
I put one too many inverses in my calculations
0
 
LVL 27

Accepted Solution

by:
BigRat earned 2000 total points (awarded by participants)
ID: 41808671
>>y'=1/x' is correct

That is ALWAYS correct simply from the definition of y' (as you have it) since y' = dy/dx and x'=dx/dy and dx/dy*dy/dx=1.

Similarly if you want to write y'' for d²y/dx² then x'' would be d²x/dy² and so y''=x''. And so on and so forth PROVIDED that such differentials exist!
0
 
LVL 27

Expert Comment

by:aburr
ID: 41836561
The only correct answer, (and a good one)
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

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

Foreword (May 2015) This web page has appeared at Google.  It's definitely worth considering! https://www.google.com/about/careers/students/guide-to-technical-development.html How to Know You are Making a Difference at EE In August, 2013, one …
This article covers the basics of data encryption, what it is, how it works, and why it's important. If you've ever wondered what goes on when you "encrypt" data, you can look here to build a good foundation for your personal learning.
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…
I've attached the XLSM Excel spreadsheet I used in the video and also text files containing the macros used below. https://filedb.experts-exchange.com/incoming/2017/03_w12/1151775/Permutations.txt https://filedb.experts-exchange.com/incoming/201…

618 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