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Math Help - Find -f(x)

  1. #1
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    Find -f(x)

    Find -f(x) for:

    (a) f(x) = 3 - x

    (b) f(x) = 1/x
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by symmetry View Post
    Find -f(x) for:

    (a) f(x) = 3 - x

    (b) f(x) = 1/x
    Are you sure that you have the question right.

    As it is it is too trivial to be worth troubling with.

    RonL
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  3. #3
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    Ron

    Ron,

    The question is exactly as appeared in the math book. I'm sure it is another plug and chug, right?

    I just get confused by the negative in front of f(x). See it?

    What do I do in this case?

    Thanks!
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  4. #4
    Forum Admin topsquark's Avatar
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    Quote Originally Posted by symmetry View Post
    Ron,

    The question is exactly as appeared in the math book. I'm sure it is another plug and chug, right?

    I just get confused by the negative in front of f(x). See it?

    What do I do in this case?

    Thanks!
    What does it mean when you have "-3" for example? I think some of the problem here is in the way you are looking at "f(x)." In the context you are looking at it f(x) is just a (probably real) number. So the negative sign is the same as it is in any other context when applied to a number.

    -Dan
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  5. #5
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    ok

    Let's see:

    -f(x) applied in f(x) = 3 - x

    Becomes 3 - (-x) = 3 + x, right?

    Or, is it - 3 + x?

    Or maybe - 3 - x?
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  6. #6
    Forum Admin topsquark's Avatar
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    Quote Originally Posted by symmetry View Post
    Let's see:

    -f(x) applied in f(x) = 3 - x

    Becomes 3 - (-x) = 3 + x, right?

    Or, is it - 3 + x?

    Or maybe - 3 - x?
    No. f(x) = 3 - x means that -f(x) = -(3 - x) = -3 + x.

    The "-" in front of the f(x) affects the entire function.

    -Dan
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  7. #7
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    ok

    Okay...the negative sign in front of the function (-f(x)) affects the whole function.

    Now it is very clear.

    Thanks!
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