Nov 23, 2008

Tri One Review Key

HERE IS THE FULL KEY. I brought home an older version of the key by accident, so if you see any possible errors please let me know.

EXTRA CREDIT FOR YOU IF YOU FIND AN ERROR!

Also, PLEASE feel free to email me if you have any questions. You could also call me @ home 952-210-6795 if you need to. I'm playing tennis at 6:00 so I won't be able to respond to you from about 5:30-8:00.

Hope this works for you.


QUESTION LOG:

On #45:
F(x)=(square root x)+3
G(x)=x2 -3
You restricted it as
(0, infinity)...but shouldn't it be (including -3, infinity)?

Answer: The best way to answer this question is with the graphs. Notice that in order to make the graph a true reflection over the line y=x, that you'd need to cut it at the vertex, which happens when x=0.


Also #31:
I did it twice and got 4x-20(square root x)+1, and you posted 4x-20(square root x) +25

Answer: I think the problem comes when evaluating -12(sqrt(x)-1)...you should get -12sqrt(x)+12, which will then give you 25 for the constant.

#48: How are they inverses if they're the same equation...? I'm confused! :(
Answer: Well, if you take f(g(x)) you should get x, right? And also g(f(x))=x...and really that is the way you would verify that they are inverses. Also, if you look at the graph, you would see that it would reflect onto itself over the line y=x (assuming f is restricted to [0,3]. It doesn't happen very often, but this is a case where a function is an inverse of itself.

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