Calc: Derivative of f(x)=3x2-7x+5 - Newbie Guide

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Homework Help Overview

The discussion revolves around finding the derivative of the function f(x) = 3x² - 7x + 5 using the definition of the derivative, specifically the limit of the difference quotient as h approaches zero.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the expression for the derivative and question its form, particularly whether it can yield a specific numerical value. There are inquiries about the presence of variables x and h in the expression and the implications of taking the limit as h approaches zero.

Discussion Status

Participants are actively engaging with the problem, with some providing guidance on the importance of showing work for better feedback. There is a mix of interpretations regarding the derivative's expression, and suggestions for alternative learning resources have been offered.

Contextual Notes

Some participants note the original poster's self-teaching approach and express concern about relying solely on online sources for learning calculus.

MarcAlexander
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1) f(x)=3x2-7x+5
2) \frac{f(x+h)-f(x)}{h}

What is the value of equation 2?

NOTE: I'm new to Calculus. I'm trying to self teach by using the internet.

Thanks in advance. ;)
 
Last edited:
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MarcAlexander said:
1) f(x)=3x2-7x+5
2) \frac{f(x+h)-f(x)}{h}

Is equation 2 equal to -7?

No, it isn't. It will have x's and h's in the expression.
 
LCKurtz said:
No, it isn't. It will have x's and h's in the expression.

May I inquire what the answer is?
 
MarcAlexander said:
1) f(x)=3x2-7x+5
2) \frac{f(x+h)-f(x)}{h}

What is the value of equation 2?

NOTE: I'm new to Calculus. I'm trying to self teach by using the internet.

Thanks in advance. ;)

2) will contain both x and h. If you mean the LIMIT as h --> 0, then that would contain only x. Even so, its value would depend on what value of x you choose.

If you show us your work we can make more meaningful comments.

RGV
 
The answer is 6x-7 to help you, but show what you did so people can tell you what is wrong.
 
iRaid said:
The answer is 6x-7 to help you, but show what you did so people can tell you what is wrong.

Would another form of 6x-7 be [PLAIN]http://www.myalgebra.com/math_image.aspx?p=3hxSMB02ESMB032SMB02eSMB03-21hx-18x-105?p=170?p=22?

That number is the result myalgebra.com calculated.
 
Last edited by a moderator:
Obviously not: one expression has x alone, while the other has both x and h.

Rather than trying to teach yourself using on-line sources, you would probably do better to read a book on the subject. Some people praise the Schaums Outlines books, but, really, most introductory books could be very helpful to you. There even several free ones available as PDF files; you can find them by doing a Google search for 'free calculus books'.

RGV
 

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