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What does 'for all real values of x' mean?

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    The question is:

    Prove, by counter-example, that the statement: " ln (3x^2 + 5x + 3) > 0 for all real values of x " is FALSE.

    What does the real values of x mean in this question? :confused:
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    I believe it means it can be any number, in this case a positive one, but not an i or j used in further maths, so for you just and positive number up to infinity whole number or decimal :yep:
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    Basically just means for all numbers from minus infinity to infinity. We say real x to distinguish from complex numbers.
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    Non-complex values of x (i.e. values of x that don't involve sqrt(-1)). If you haven't done FP1, then you have no need to even contemplate sqrt(-1), so don't worry about it, and just read it as "for all values of x". They just need to put the word "real" in there because otherwise some smartarse who's studied complex numbers will go and give a solution that the markers weren't expecting.
  5. Offline

    Oh so basically any number...! Thanks guys


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