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I need to plot $2^{x^{2}}$ without using calculus. I would like to know how to explain why that function is smooth at $x=0.$

  • Do you want to plot on paper or a graphing calculator? The former can be done by computing several points (in this case, around $x=0$). – Argon May 28 '12 at 18:53
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    Maybe you can argue that since both $2^x$ and $x^2$ are smooth at $x=0$ then so is the composition (that's the most "without using calculus" I get since smooth is a term in calculus ;)) – Belgi May 28 '12 at 18:53
  • @Argon: On a paper. But I failed to notice how it is "smooth". –  May 28 '12 at 19:28
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    you know that $x^2$ and $2^x$ are smooth and behave 'reasonably'. Why would their composition not? If you want a proof, not just intuition, then you'll need calculus, since that's where the definition of smooth comes from. – Robert Mastragostino May 28 '12 at 19:29
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    Why anyone would want to plot this without the tools of calculus is beyond me.But I guess it's a standard pre-calculus grind-it-out problem.One question I WOULD have for such a problem before answering is what does "smooth" mean in this particular problem-that derivatives of all orders exist and are continuous? I wouldn't think so given how the question is asked. – Mathemagician1234 May 28 '12 at 19:54
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    To save some work, notice that the function $2^{x^2}$ is even (ie. symmetric wrt the y-axis), so you only need to plot the graph for positive $x$ and the rest you get by mirroring that. – Mikko Korhonen May 28 '12 at 19:56

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