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Math Help - If F(x)=x^2+1 when F(x)=(a-1)

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    If F(x)=x^2+1 when F(x)=(a-1)

    I had this question on a state test... what do you guys think it is?? Its been years since I've done math and was kinda mad when i received this question because it showed me how much i'd forgotten



    If your answer matches something below, show your work please to me and tell me i should go back to school, Thanks guys


    choices were
    A.) a^2
    B.) a^2+2
    C.) a^2-2a
    D.) a^2+2a
    E.) a^2-2a +2
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  2. #2
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    Re: If F(x)=x^2+1 when F(x)=(a-1)

    Quote Originally Posted by shirania View Post
    If F(x)=x^2+1 when F(x)=(a-1)
    I have no idea what this is supposed to mean. Could you post the question exactly as it was worded? Or explain what it was asking you to find?


    Edit: Looking at the answers, I'm guessing you were asked to evaluate F(a-1)?

    In that case,

    F(x) = x^2 + 1

    \Rightarrow F(a-1) = (a-1)^2 + 1

    Now expand and collect like terms.
    Last edited by Reckoner; July 12th 2012 at 07:32 PM.
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    Re: If F(x)=x^2+1 when F(x)=(a-1)

    the quest was
    "If f(x)=x^2+1, then f(a-1)= what?" wanna say that is basically how it was worded.

    (a-1)^2+1 is a^2-2a+3? right
    so that would make the answers invalid??
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    Re: If F(x)=x^2+1 when F(x)=(a-1)

    Quote Originally Posted by shirania View Post
    the quest was
    "If f(x)=x^2+1, then f(a-1)= what?" wanna say that is basically how it was worded.

    (a-1)^2+1 is a^2-2a+3? right
    so that would make the answers invalid??
    I don't know where you are getting the three from.

    f(a-1) = (a-1)^2 + 1

     = (a-1)(a-1) + 1

     = a^2 - 1a - 1a + 1^2 + 1

     = a^2 - 2a + 2
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    Re: If F(x)=x^2+1 when F(x)=(a-1)

    ... BECAUSE i'm FREAKING STUPID.... LOL HAHAHHAHAHAHA 1^2 whole time i've been doing 1+1 in my head lol hahahahhaha wow i'm amazing... thanks bro lol lol
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