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07-19-2018 02:09 PM
I am trying to take a negative number(cell) and take it to the power of 1.852. I am getting an error stating, "ERROR:(X<0)", on the excel spreadsheet, how can I get around this problem so that its able to calculate negative numbers? your help would be appreiated.
07-19-2018 02:38 PM
Since a negative number to a fractional power yields a complex number, you'll have to turn on the "Allow complex output from real input" setting. To do this, press Shift Home (Settings), then press left-cursor twice to highlight the check box near the bottom of the screen. Press the + key and see that a check appears in that box. Your spreadsheet cell will now work without an error.
However, do you really want complex numbers in your spreadsheet?
Disclaimer: I don't work for HP. I'm just another happy HP Prime user.
07-19-2018 03:37 PM
Thanks a lot Joe, really helpful info. Its not quite giving me the solution I was hoping for(negative answer), its now reporting the answer as a positive value. I'll give it some more time to try and understand the calculator
Exactly what number are you raising to exactly what power? Try it in Home view (or on any other calculator), and you'll see that the answer you're expecting is NOT the correct answer. For example, (-1.23) raised to the (2.34) power does NOT yield a negative answer. OR a positive answer. It yields a complex number, namely 0.782 + 1.422 times i . In the Spreadsheet app, you might have to tap the View button to see the entire complex number.
07-19-2018 03:47 PM - edited 07-19-2018 03:56 PM
Aha... I strongly suspect that the trouble you're running into is being caused by the difference between -X^Y and (-X)^Y.
-1.23 ^ 2.34 = -1.623 (a negative result as you apparently expected)
(-1.23) ^ 2.34 = 0.782 + 1.4224*i
Please note that the first example above is NOT a negative number being raised to a power. Algebraic order of operations performs powers BEFORE negations. So the 1.23 (a positive number) is raised to the 2.34 power, and the result of that is THEN made negative by that negative sign in front. It might be more helpful to think of it like this:
-1.23 ^ 2.34 = - (1.23^2.34)