Are these the correct expressions for ## dF/dy' ##?

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Homework Help Overview

The discussion revolves around finding the expressions for the derivative ## dF/dy' ## based on different functions of ## y' ##, specifically focusing on the functions ## F(y')=(1+y'^2)^{\frac{1}{4}} ##, ## F(y')=sin(y') ##, and ## F(y')=exp(y') ##. Participants are verifying the correctness of derived expressions and clarifying the notation used.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants present their derived expressions for ## dF/dy' ## and seek verification. Questions arise regarding the notation of ## y' ## and the meaning of 'exp' in the context of the problem.

Discussion Status

Some participants have confirmed the correctness of the expressions derived for the first two functions. However, there remains uncertainty regarding the notation and the interpretation of the third function involving 'exp'. The discussion is ongoing with participants exploring different interpretations and clarifications.

Contextual Notes

There is a noted confusion regarding the use of primes in the variable names and the implications of such notation. Additionally, the absence of relevant equations in the original post may limit the context for some participants.

Math100
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Homework Statement
Find the expressions for ## dF/dy' ## when
a) ## F(y')=(1+y'^2)^{\frac{1}{4}} ##
b) ## F(y')=sin (y') ##
c) ## F(y')=exp(y') ##
Relevant Equations
None.
a) ## dF/dy'=\frac{1}{4}(1+y'^2)^{\frac{-3}{4}}\cdot 2y' ##
b) ## dF/dy'=cos (y') ##

I just took the derivatives above and found out these expressions, but may anyone please check/verify to see if these expressions for ## dF/dy' ## are correct? Also, I do not understand part c). What does 'exp' indicate in here?
 
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Math100 said:
Homework Statement: Find the expressions for ## dF/dy' ## when
a) ## F(y')=(1+y'^2)^{\frac{1}{4}} ##
b) ## F(y')=sin (y') ##
c) ## F(y')=exp(y') ##
Relevant Equations: None.

a) ## dF/dy'=\frac{1}{4}(1+y'^2)^{\frac{-3}{4}}\cdot 2y' ##
b) ## dF/dy'=cos (y') ##

I just took the derivatives above and found out these expressions, but may anyone please check/verify to see if these expressions for ## dF/dy' ## are correct? Also, I do not understand part c). What does 'exp' indicate in here?
##\exp(y')## means ##e^{y'}.##

What you wrote is correct, but why is there a prime at the ##y##'s? The same could be written with just ##y## or ##t## as the variable name. ##y'## normally indicates a derivative.
 
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fresh_42 said:
##\exp(y')## means ##e^{y'}.##

What you wrote is correct, but why is there a prime at the ##y##'s? The same could be written with just ##y## or ##t## as the variable name. ##y'## normally indicates a derivative.
I don't know either. So what should the book normally express these primes then, instead? Also, if ## exp(y') ## mean ## e^{y'} ##. Then the expression for ## dF/dy' ## is ## dF/dy'=e^{y'} ##?
 
Math100 said:
I don't know either. So what should the book normally express these primes then, instead? Also, if ## exp(y') ## mean ## e^{y'} ##. Then the expression for ## dF/dy' ## is ## dF/dy'=e^{y'} ##?
Yes.
 
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fresh_42 said:
Yes.
Thank you so much for verifying!
 

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