Why is SolveCubic in CAS view not returning all solutions?

Alasdair shared this question 5 months ago
Answered

When I enter

f(x) := x^3 - 4x - 2

which has three real solutions, the command "Solve(f)" gives the three solutions numerically, but the command "SolveCubic(f)" only returns one of them:

{<solution>, ?, ?}

The other two solutions are given as question marks. How can I obtain the other two closed-form solutions, as the documentation claims? I'm using version 6.0.562.0-win.

Thank you!

Comments (2)

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version 5

/AAAAAElFTkSuQmCC

version 6

/HQAAAABJRU5ErkJggg==

what are you using?

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Thank you; I'm not quite sure which version I was using (though I thought it was fairly recent); anyway just now I deleted that one and installed a new version 6. And now it works.

Thanks again!

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