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Finding an inverse

  • Thread starter wegnes
  • Start date
  • #1
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Homework Statement



(x+2)^2(x-3) I am asked does an inverse exist for all real numbers? then I am asked can I restrict the domain and force and inverse to exist?

Homework Equations


I said no because the function is not one-to-one when graphed.


The Attempt at a Solution

I thought it I took the square root of the x's in the original equation then this would work.
 

Answers and Replies

  • #2
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Okay, I'll warn you that if you don't clean this up you'll get reamed!
You're given a function. Let's call it f(x) and define it to be equal to (x+2)^2(x-3)
Now you're asked to take the inverse. Do that. There is one REAL value of x for which the inverse is undefined. This should be poignantly obvious. Part two of that question will make sense once you figure out part 1.
 
  • #3
HallsofIvy
Science Advisor
Homework Helper
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I'm afraid BrendanH has misunderstood the problem. You are not asked to take the inverse and are a whole lot more than ONE value at which that does not have an inverse!

wegnes, you say you have graphed it and know that it does not have an inverse because it is not one-to-one. Excellent! Now, on what intervals is the function one-to-one? There are several of those and so several different ways to restrict the function so that the restiction does have an inverse.

Since the question does not ask you to actually find an inverse, it is not necessary to "take the square root" or anything like that.
 
  • #4
6
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Thank you! That what I wasn't doing! You are a big help, I apreciate it;o)
 

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