Finding the Local Maximum Point for f(x)=xe^(-ax)

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Homework Help Overview

The discussion revolves around finding the local maximum point for the function f(x) = xe^(-ax), where x is a real number and a is a positive constant. Participants are tasked with showing that the function has a local maximum and expressing the coordinates of this point in terms of a.

Discussion Character

  • Mathematical reasoning, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants discuss the calculation of the derivative using the product rule and question the correctness of each other's attempts. There is a focus on ensuring the derivative is accurately derived before proceeding with finding critical points.

Discussion Status

The conversation is ongoing, with participants providing feedback on each other's derivative calculations. Some guidance has been offered regarding the use of the product rule, and there is a sense of collaboration as they clarify their understanding of the derivative before moving forward.

Contextual Notes

There is an emphasis on the correct application of differentiation rules, and participants are navigating through potential misunderstandings about the derivative's formulation. The discussion reflects a learning process where assumptions and definitions are being scrutinized.

Joza
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Local maximum point...

Homework Statement



f(x)=xe TO THE POWER OF -ax x E R a > o

Show that f(x) has a local maximum and express this point's coordinates in terms of a.

The Attempt at a Solution



I think dy/dx = -axe TO THE POWER OF -ax

Correct?

I don't know where to go after this.
 
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Your derivative is wrong. Remember the product rule?
 
Oh product...

Ok so... xe^-ax + e^-ax(1)

Is that right?
 
You used to have a (-a) in front of the first term. Where did that go? I liked it.
 
Ok, I mie be wrong here.

(u)dv/dx + (v)du/dx

So... (x)-ae^-ax + e^-ax( 1) = -axe^-ax + e^-ax

Correct?
 
Finally! Rest of the problem is easy, right?
 
I let it = 0 and solve to get values for x?
 
I think so. Correct me if I'm wrong. :smile:
 
Now, Dick, have you ever been wrong?
 
  • #10
More times than I can count. I was betting on the Bears last night.
 

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