SwissMicros Calculator Forum

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...

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.

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...

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...

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 ...

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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...

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...

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 ...

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 ...