# Approximate value of delta-y

Dear experts,

In the attached screen I have shown the text from ‘application of derivatives’ discussing the calculation of approximate values of delta-n.

Can someone please explain the steps n text between 2 and 3.

I am having a challenge to understand how delta-x=delta-y has been arrived by the substitution.

Thank you
###### Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Author Commented:
Dear experts,

Please find attached the pic i was referring to.

kindly help.

Thank you
WhatsApp-Image-2018-02-24-at-14.28.2.pdf
0
Commented:
This line is clearly in error:
If we take y = f(x) = x in (1)

y = f(x)  is true by definition      But neither y nor f(x) is equal to x.  And none of these terms is relevant to Eq (1).

I think the point of all this is to understand that derivative of the function f(x) at x is (approximately equal) or (equal in the limit) to the slope as defined by delta_x/delta_ y (where delta is the little differential triangle).
0

Experts Exchange Solution brought to you by

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

###### It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Math / Science

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.