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A comment on Windows Calculator invalid input with 10^x function. Parent comment

Re:Windows Calculator invalid input with 10^x function by barbegal on Thursday August 02, 2018 @05:53PM (#17675777)
10^0.043429 ~= e^0.1

10^0.0043429 ~= e^0.01

10^0.00043429 ~= e^0.001

So that gives some insight into the algorithm that is being used

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Re:Windows Calculator invalid input with 10^x function by gabriel34 on Thursday August 02, 2018 @07:18PM (#17676246)
Using this we can actually predict the smallest exponent that fails for other bases:

  base	exponent (6 digits)
  10	0.043429
  11	0.041703
  12	0.040243
  2	0.144271
  3	0.091024
  4	0.072135
  1000	0.014476
(the calculated exponent for two is actually 0.144270, but since it ends in zero the first failure occurs at 0.144271)
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Re:Windows Calculator invalid input with 10^x function by imran3740 on Thursday August 02, 2018 @10:07PM (#17676848)
Just checked, calc fails at 11^0.41703 (curiously not at 41703, but 41704, maybe a floating point thing). Maybe it changes base to e and uses the Taylor series for e^x, but fails if x is too precise for what it expects?
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Re:Windows Calculator invalid input with 10^x function by psyklic on Thursday August 02, 2018 @11:44PM (#17677157)
Fantastic, that confirms it! And kudos to barbegal for recognizing the base.
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