Drawing a derivative of a function

In summary, the conversation discusses sketching a derivative of a function, with the derivative being the slope of the line tangent to the function's graph. The derivative is positive at x=0, increases until it reaches a maximum at x=1, then decreases until it becomes zero at x=2.5. It then continues to decrease and becomes negative. The derivative also attains a value of 1 somewhere between x=0.5 and 1.5, and the slope of the secant line from x=0.5 to x=1.5 is slightly greater than 1. The derivative at x=0 is less than 1.
  • #1
dbag123
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3
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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  • #2
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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  • #3
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
 
  • #4
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.
 

1. What is a derivative of a function?

A derivative of a function is a mathematical concept that represents the rate of change of the function at a specific point. It is essentially the slope of the function at that point.

2. How is a derivative of a function calculated?

A derivative can be calculated using the limit definition, which involves finding the slope of the function at two points that are very close together. It can also be calculated using rules such as the power rule, product rule, and chain rule.

3. What is the purpose of finding a derivative of a function?

The purpose of finding a derivative of a function is to understand the behavior of the function. It can help determine the maximum and minimum points, the direction of the function, and the rate of change at a specific point.

4. Can a derivative of a function be negative?

Yes, a derivative of a function can be negative. This indicates that the function is decreasing at that point.

5. Are there any real-world applications of finding a derivative of a function?

Yes, derivatives have many real-world applications, such as in physics to calculate velocity and acceleration, in economics to determine marginal cost and revenue, and in engineering to optimize designs and processes.

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