Search found 615 matches

by Thomas Okken
Sun Jan 31, 2021 9:16 pm
Forum: Usage tips, tricks and problem reports
Topic: third root of -8...
Replies: 17
Views: 799

Re: third root of -8...

Hi Thomas, Sorry, but in my monitor, the square root symbol appears almost exactly the same as the division one, and that confused me. In fact I had to apply a very big zoom before realizing that you in fact wrote 1+i sqrt(3), and not 1+i/3, as I first read. Oh! I see. That's not good, I wasn't awa...
by Thomas Okken
Sun Jan 31, 2021 8:07 pm
Forum: Usage tips, tricks and problem reports
Topic: third root of -8...
Replies: 17
Views: 799

Re: third root of -8...

ManuMa wrote:
Sun Jan 31, 2021 7:19 pm
Thomas Okken wrote:
Sun Jan 31, 2021 11:41 am
...
-8^(1/3) = e^(ln(-8)/3) = 1+i√3. ...
Hi Thomas,
I think a number fell out of your equation, as:
-8^(1/3) = e^(ln(-8)/3)) = 2e^(i pi/3) = 1+1.7321i

Regards,
Manuel.
Nothing fell out. What I wrote is correct.
by Thomas Okken
Sun Jan 31, 2021 11:41 am
Forum: Usage tips, tricks and problem reports
Topic: third root of -8...
Replies: 17
Views: 799

Re: third root of -8...

Most calculators will give -2 as a result for -8^1/3... I'm new to the DM42 (and Free42 for that matter) but I still think that with RRES enabled, "Invalid data" is a wrong answer or, at least, misleading. Please correct me if I'm wrong. Y to the power 1/X is not the same as the X-th root...
by Thomas Okken
Sat Jan 30, 2021 5:21 pm
Forum: Usage tips, tricks and problem reports
Topic: third root of -8...
Replies: 17
Views: 799

Re: third root of -8...

But with RRES enabled, the cuberoot( -8 ) gives "Invalid data" (therefore: an error), which is ... not exactly correct. Unless you found an actual cube root function somewhere on the DM42, what you're actually calculating is -8 to the 1/3 power, and that is not a real number. So Invalid D...
by Thomas Okken
Sat Jan 30, 2021 4:00 pm
Forum: Software Library
Topic: Collection of functions for DM42/Free42 (updated on 2021-02-23)
Replies: 63
Views: 1835

Re: Collection of functions for DM42/Free42

Note that the next version of Free42 has a change to the RTNERR function, which will take the error number as an argument rather than from the X register. So you'd write RTNERR 4 instead of 4 RTNERR. Old programs will be converted automatically, translating RTNERR without arguments to RTNERR IND ST ...
by Thomas Okken
Tue Jan 19, 2021 3:26 pm
Forum: Usage tips, tricks and problem reports
Topic: Question about a result
Replies: 15
Views: 745

Re: Question about a result

I think it strange that HP calculators and derivates are not able to find the real solution -1.0458. Since what you're calculating is not actually the 11th root but the 1/11th power, the results you are getting are correct. If a calculator has an "x-th root of y" button, it is not unreaso...
by Thomas Okken
Fri Jan 15, 2021 11:55 pm
Forum: DM42
Topic: "Internal error" message
Replies: 1
Views: 228

Re: "Internal error" message

If CLP "" returns Internal Error, that indicates that the current program pointer has become invalid for some reason. That could be a Free42 bug, but it will be difficult to troubleshoot unless you are able to reproduce the problem from a fresh state. In the meantime, though, you should be...
by Thomas Okken
Fri Jan 15, 2021 12:27 am
Forum: Discuss!
Topic: Delivery To Canada (Quebec)
Replies: 8
Views: 495

Re: Delivery To Canada (Quebec)

Yesterday, my mother told me that she had just received a parcel that her sister had sent her two weeks before Christmas.
Mom lives in the Netherlands and her sister in Germany...
by Thomas Okken
Tue Jan 12, 2021 12:56 pm
Forum: DM42
Topic: Memory management?
Replies: 4
Views: 424

Re: Memory management?

I'm guessing (i.e. I haven't read the source) that Free42 is just reporting the amount of memory that OS tells it is available, in other words however much it could malloc for its own use. Yes and no... the Free42 MEM calls a shell function, shell_get_mem(), and displays whatever it returns. So to ...
by Thomas Okken
Fri Jan 08, 2021 5:09 pm
Forum: Usage tips, tricks and problem reports
Topic: minor inconsistency
Replies: 9
Views: 478

Re: minor inconsistency

Once I had decided that my scientific programmable RPN calculator app was going to be modeled after the HP-42S, I felt it made sense to make it mimic the 42S as closely as possible. I find it annoying when simulators only approximate what they simulate, because it tends to trip me up when my muscle ...