Solution 36476: Resolving a Nonreal Answer Error on a TI-84 Plus C Silver Edition
How do I resolve a Nonreal Answer error when using a TI-84 Plus C Silver Edition?When entering calculations in real mode, "ERR:NONREAL ANS" is returned if the answer to a problem contains an imaginary number. For example, if your handheld is calculating in real mode, and you try to compute for the square root of negative one, you get the following error message:
To resolve this error, first, ensure that the problem is entered correctly. If the problem is entered correctly and you're expecting an imaginary number as part of the answer, you would need to change the number format settings. To do so, press the [MODE] button, select the option for "a+bi", and press Enter.
Press [CLEAR] to exit the mode screen. Now, when you attempt to compute calculations with imaginary results (such as the square root of negative one), you'll get an answer.
For more information, please see the TI-84 Plus C Silver Edition guidebook.