Sunday, September 20, 2009

Alaina's reflection

I am super excited with LOGS!!!!! They are my favorite. I completely don't understand how people have trouble with them.

log24=2
it implies that 2^2=4
the subscript 2 is your base
4 is your answer
2 is the exponent

I still don't really understand proving something is an inverse. I get that you have to plug in a -x for the x-axis, a (-x) for the y-axis, but i don't understand what I am supposed to do afterwards. I know that I have to plug in the what I have as the inverse into f(-f(x)) and -f(f(x)). I guess it is just a matter of me understanding the notes so I'll probably read over them and try to figure it out on my own, but if I have any questions, I will be asking in class.

2 comments:

  1. well I wasnt there for the inverse stuff but I hope this helps you out a little. For inverses instead of solving for y you switch it around and solve for x, and that's about all I really know about this because im still waiting on B-rob and I to go over the work from Thursday and Friday

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  2. proving inverses..

    plug x into one function, plug that function into the inverse function, and then simplify) and verify that you end up with just "x". Here's what it looks like:

    Determine algebraically whether f (x) = 3x – 2 and g(x) = (x + 2)/3 are inverses of each other.

    I will plug the formula for g(x) into every instance of "x" in the formula for f (x):

    (fog)(x)= f(g(x))

    = f(x +2/3)

    = 3(x +2/3)-2

    = (x + 2)-2

    = x

    Now I will plug the formula for f (x) into every instance of "x" in the formula for g(x) :

    (gof)(x)= g(f(x))

    = g(3x-2)

    = (3x-2/3)+2

    = 3x/3

    = x

    Both ways, I ended up with just "x", so f (x) and g(x) are inverses of each other.

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