Re: Bug in 21, 25 - y raised to the x Message #2 Posted by Ernie Malaga on 18 Dec 2002, 5:05 p.m., in response to message #1 by Don Davis
Don:
This "bug" is present in the oldest HP calculators. I suppose it's due to the fact that powers were calculated by way of logarithms, and you can't apply the LN function to a negative number. More modern calculators circumvent this problem by analyzing both numbers, and work the sign of the result based on that. If I'm not mistaken, the HP-67/97 were the first calculators to be able to raise negative numbers to whole powers.
By the same token, the oldest machines allowed you to CHS the number zero, and I think I read somewhere that the HP-35 gave an error message if you tried to calculate the square root of -0. More modern calculators don't change the sign of zero no matter how many times you press CHS.
Ain't life innerestin'?
-Ernie
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