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Easy question
09-09-2021, 11:59 PM (This post was last modified: 09-10-2021 12:36 AM by ijabbott.)
Post: #17
RE: Easy question
The result of (-1)^(4/5) will depend on whether or not you have the "Allow complex output from real input" option turned on or off in the settings. If turned off, you will get the real result -1. If turned on, you will get the complex result -0.809016994375+0.587785252292*i. Also, I think the CAS mode always approximates to the complex result.

Since -1 is e^(i*π), (-1)^(4/5) is (e^(i*π))^(4/5), which is e^(i*π*4/5) in exponential form, or 1∡(π*4/5) in polar form (radians mode), or cos(π*4/5)+sin(π*4/5)*i in rectangular form (radians mode).

In CAS mode, pow2exp((-1)^(4/5)) produces e^((4/5)*i*π).

— Ian Abbott
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Messages In This Thread
Easy question - boggiano - 09-01-2021, 10:10 AM
RE: Easy question - roadrunner - 09-01-2021, 11:54 AM
RE: Easy question - rawi - 09-01-2021, 04:02 PM
RE: Easy question - toml_12953 - 09-01-2021, 04:11 PM
RE: Easy question - jte - 09-06-2021, 12:36 AM
RE: Easy question - Albert Chan - 09-06-2021, 01:17 AM
RE: Easy question - ijabbott - 09-06-2021, 12:41 PM
RE: Easy question - jte - 09-06-2021, 10:31 PM
RE: Easy question - Albert Chan - 09-07-2021, 01:09 AM
RE: Easy question - jte - 09-09-2021, 05:55 PM
RE: Easy question - jte - 09-06-2021, 05:39 PM
RE: Easy question - boggiano - 09-09-2021, 10:44 AM
RE: Easy question - Joe Horn - 09-09-2021, 05:40 PM
RE: Easy question - boggiano - 09-09-2021, 06:05 PM
RE: Easy question - toml_12953 - 09-09-2021, 10:10 PM
RE: Easy question - boggiano - 09-09-2021, 10:32 PM
RE: Easy question - ijabbott - 09-09-2021 11:59 PM
RE: Easy question - Albert Chan - 09-10-2021, 05:23 PM
RE: Easy question - ijabbott - 09-10-2021, 06:09 PM
RE: Easy question - boggiano - 09-11-2021, 12:16 AM
RE: Easy question - toml_12953 - 09-11-2021, 11:14 AM



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