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Wrong answer when evaluating log(10^-12) - Daniel Greenidge - 01-26-2012 Hello everyone, I know from the power property that log(10^-12) should be -12. Wolfram-Alpha corroborates this. However, when I evaluate this on both my HP 15C and 50g, the answer turns out to be -11. Here are the exact keystrokes I am using for my 15C:
10 Any ideas why this might be?
Thank you, Re: Wrong answer when evaluating log(10^-12) - Bart (UK) - 01-26-2012 Hint:
Edited: 26 Jan 2012, 11:26 a.m.
Re: Wrong answer when evaluating log(10^-12) - Gerson W. Barbosa - 01-26-2012 Quote: The answer is right. The input is wrong. You're actually entering 10*10 -12, that is, 101 * 10 -12 = 101-12 = 10-11 Enter the mantissa first, then press EEX and enter the exponent:
1 When the mantissa is 1, it can be omitted.
Gerson.
Re: Wrong answer when evaluating log(10^-12) - Daniel Greenidge - 01-26-2012 Thank you for your help! I feel a bit imbecilic right now but I certainly shall not repeat my mistake.
Regards, Re: Wrong answer when evaluating log(10^-12) - Gerson W. Barbosa - 01-26-2012 Quote: Bart, I hadn't read your post yet when I said the answer of the calculator was right. "Expected answer" appears to be a more didactic expression, I should have used it myself. By the way, my HP-15C gave a lot of "wrong answers" to me, especially in the beginning, when it was just replacing a TI-59. Oh, and more recently, just some threads below my HP-42S was refusing to give me the answers I expected :-) Regards,
Gerson. Edited: 26 Jan 2012, 6:53 p.m.
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