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|    sci.math.symbolic    |    Symbolic algebra discussion    |    10,432 messages    |
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|    Message 8,539 of 10,432    |
|    Richard Fateman to Axel Vogt    |
|    Re: should CAS resturn infinity for dive    |
|    20 Mar 14 15:44:34    |
      From: fateman@cs.berkeley.edu              On 3/18/2014 1:35 PM, Axel Vogt wrote:       pt.       >       > PS: big grin for limit cos(x) or sin(x) = interval. I consider       > such as a smart answer by Maple, giving an interval as estimate,       > indicating "system gives up for details"       >              I suppose one can have a discussion on whether this is helpful       or meaningful, or consistent with the notion of interval.              I tend to think of an interval [-1,1] to mean that the true result       is a particular number v such that -1<=v<=1. In the limit       example, the result is apparently saying that there is no such v.       Rather the value as x->oo is bounded.              And then there are these problems.              we know that if lim f(x) = A and lim g(x) = B then lim f(x)*g(x) = AB              from these programs we learn that lim sin(x) = lim cos(x) = [-1,1]       also of course lim sin(2*x) = [-1,1].       putting these results together with              sin(2*x) = 2*sin(x)*cos(x)              and take the limit as x->oo we learn that       [-1,1] = 2*[-1,1]*[-1,1] = [-2,2].              Backtrack here and try to figure out what we did that went wrong.                     << exercise for the reader>>              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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