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Quick Factoing Question

  1. Feb 10, 2008 #1
    Can someone help me factor x^3 + 8? I totally forgot how to do that :S
  2. jcsd
  3. Feb 10, 2008 #2
    We must note that this is an expression of the form a^3+b^3=(a+b)(a^2-ab+b^2), where in this case a=x and b=2.
  4. Feb 10, 2008 #3


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    Homework Helper

    Usually to factor things ,use the remainder and Factor theorem.

    Let f(x)=x^3 + 8
    try f(1,-1,2,etc) and when you get x=a such that f(a)=0. x-a is a factor of f(x)

    For your example; f(-2)=0 so that x+2 is factor of f(x)...you can use synthetic division or long division to get the other factor.
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