Drawing a derivative of a function

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Homework Help Overview

The discussion revolves around the graphical representation of a derivative of a function, specifically how to accurately sketch the derivative based on the behavior of the original function.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the characteristics of the derivative in relation to the original function, questioning the accuracy of the initial approximation and exploring the behavior of the derivative at specific points, such as where it increases or decreases.

Discussion Status

Some participants have provided observations about the behavior of the derivative, noting specific points of interest and suggesting that the graph should reflect certain characteristics of the original function. There is an ongoing exploration of the relationship between the function and its derivative.

Contextual Notes

Participants are working with a visual representation of the function and its derivative, and there are references to specific points on the graph that may influence the interpretation of the derivative's behavior.

dbag123
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Homework Statement
Draw a derivative of a function
Relevant Equations
-
243898

Red line being the function and blue an approximation of the derivative. Does it look right?
 
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dbag123 said:
Problem Statement: Draw a derivative of a function
Relevant Equations: -

View attachment 243898
Red line being the function and blue an approximation of the derivative. Does it look right?
Almost. I think at the beginning (around ##x=\frac{1}{2}##) the curve gets steeper for a moment before it flattens again, so the derivative there should first increase a bit. I think at ##3/5## is an inflection point.
 
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fresh_42 said:
Almost. I think at the beginning (around ##x=\frac{1}{2}##) the curve gets steeper for a moment before it flattens again, so the derivative there should first increase a bit. I think at ##3/5## is an inflection point.
Thank you
 
dbag123 said:
Problem Statement: Draw a derivative of a function
Relevant Equations: -
(Image removed for this reply)

Red line being the function and blue an approximation of the derivative. Does it look right?
You were to sketch the derivative, ƒ'(x), of the function, the derivative being the slope of the line tangent to
y = ƒ(x) at x assuming the graph of ƒ is given in red.

Looking at the graph:

The derivative is positive at x=0, and appears to increase as x increases from x=0 to somewhere in the neighborhood of x=1, at which location, the derivative is a maximum. From there the derivative decreases to zero at about x=2.5. (At this location the function itself is a maximum.) From here, the derivative continues to decrease, becoming more and more negative for the remainder of the graph.

Notice that near x=0.5 and x=1.5, the derivative is very nearly 1 .
Also, the slope, ##\dfrac{f(1.5)-f(0.5)}{1.5 - 0.5} ##, of the secant line from x0.5 to x=1.5, is a little bit greater than 1. The derivative attains this value somewhere between x=0.5 and 1.5. (Mean Value Theorem).
Since the derivative increases from x=0 to x=0.5 (and a little beyond), the derivative at x=0 is less than 1.

Your graph of the derivative should reflect these ideas.
 

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