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Math Help - finding a and b (question must be completed by 11 o'clock tonight!!)

  1. #1
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    finding a and b (question must be completed by 11 o'clock tonight!!)

    f(x)= (x^2 - 1) / (x - 1) if x<1
    = ax^2 - bx + 1 if 1 <= x < 3
    = 4x - a + b if x => 3

    find a and b

    all i know so far is that you must use a limit as x approaches 1 in the first equation to get 2

    then where should i go?

    thank you for your help
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  2. #2
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    What exactly are you asking?

     f(x)= \frac{x^2 - 1}{x - 1}= \frac{(x - 1)(x+1)}{x - 1} = x + 1 , x\neq 1
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  3. #3
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    sorry
    this is what the question is

    find a and b
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  4. #4
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    Quote Originally Posted by chris097 View Post



    sorry
    this is what the question is

    find a and b
    I suppose we're meant to assume that the question said something like "Find the values of a and b so that f(x) is continuous for all values of x" ....? Solve the following two equations simulataneously (I suggest you simplify them first):

    1 + 1 = a - b + 1

    a(3)^2 - b(3) + 1 = 4(3) - a + b


    And since your deadline suggests that this is assignment that in all likelihood counts towards you final grade and is therefore meant to be your own work, the thread is now closed.
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