Uncovering the Mystery of Graph 2: Analysis & Explanation

AI Thread Summary
Graph 2 is analyzed in the context of the function y = x^2, which is not one-to-one and therefore does not have a true inverse. The discussion highlights that while the inverse function appears to be y = √x, this only applies for x ≥ 0 and does not satisfy the definition of a function due to multiple x-values corresponding to a single y-value. The confusion arises from the expectation that the inverse graph should resemble a specific shape, but the properties of the original function prevent this. The conclusion emphasizes that the definition of an inverse function requires it to be one-to-one, which y = x^2 fails to meet. Understanding these properties is crucial for correctly interpreting the relationship between functions and their inverses.
temaire
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Homework Statement


http://img220.imageshack.us/img220/2813/graphmo4.jpg​
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Homework Equations


Not necessary


The Attempt at a Solution


The answers that I have up there are correct, but I was wondering why graph 2 did not look something like this:
http://img218.imageshack.us/img218/256/graph2rx8.jpg
 
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Let y=x^2 so x=sqrt(y)

so f^{-1}(x)=\sqrt{x} and f^{-1}(f(x))=\sqrt{x^2}
 
In fact, the inverse of y=x^2 is y=\sqrt{x}, x \geq 0 and y=-\sqrt{x}, x < 0. It doesn't matter in the end, however, because the definition of an inverse says that f^-1(f(x)) = x
 
Actually, that's a seriously bad question! Since y= x2 is not one-to-one, it does not have an inverse! temaire, the graph you showed would be the "inverse function" to x2 but, as you can see from the graph, there are two values of x for each positive y and so it is not a function.,
 
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