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Homework Help: If f(x) = 10-x² f(x + h) = ?

  1. Jul 25, 2010 #1
    1. The problem statement, all variables and given/known data

    if f(x) = 10-x²
    f(x + h) = ?


    2. Relevant equations

    not applicable

    3. The attempt at a solution

    no clue
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Jul 25, 2010 #2
    Simply plug,

    [tex](x+h)[/tex]

    Into all the terms that contain an [tex]x[/tex].
     
  4. Jul 25, 2010 #3
    thank you!
     
  5. Jul 26, 2010 #4

    Mentallic

    User Avatar
    Homework Helper

    Yep it's as simple as that!

    [tex]f(x)=10-x^2[/tex]

    [tex]f(x+h)=10-(x+h)^2[/tex]

    [tex]f(a)=10-a^2[/tex]

    [tex]f(2)=10-2^2=6[/tex]

    [tex]f(\sqrt{10})=10-(\sqrt{10})^2=0[/tex]

    I think you get the point :smile:

    Oh and if you choose some number a such that f(a)=0, this means that a is a root of the equation y=f(x). Such as that last example with the [itex]\sqrt{10}[/itex].
     
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