Displaying all roots of a number

[Hal Bitton in Boise]

Hi Everybody,

Does the 50G (or 48g for that matter) have any functionality whereby all the roots of a number (namely a complex number) can be displayed? Ie...if I take the fifth roots of a complex number, I would be able to see all five roots.

Thanks and best regards, Hal

[Michael Andersson]

Hi,
You should be able to use "PROOT" for this purpose. The command gives all the roots of an arbitrary polynomial and by transforming your problem into a plynomial equaton by setting the coefficient you don't need to zero you can find the roots.

For example to find all the fifth roots to 2+3i transform this into the equation -z^5+(2+3i)=0, on the 50g put

[ -1 0 0 0 0 (2,3) ]

(where the zeros are the coefficients for z^4 down to z^1) on the stack and press PROOT (found under "NUM.SLV"/"POLY").

The results is (approximately):
(1.27 , 0.25)
(-0.88 , -0.95)
(0.15 , 1.28)
(0.63 , -1.13)
(-1.17 , 0.54)

Hope this works.

Regards
Michael

[Hal Bitton in Boise]

Thanks Michael,

That works nicely.