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### Solving Equations for Complex Numbers

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```I've set the CAS to complex mode, but the symbolic commands don't produce
complex solutions, e.g.
'4*x^3+8*x-4' SOLVEVX
gives an empty list.

Am I doing something wrong? Does the CAS understand complex numbers?
```
 0

```In article
<1134924023.58fec87c58f249b740f40b921c33786d@roc.usenetexchange.com>,
Borris <none@none.com> wrote:

> I've set the CAS to complex mode, but the symbolic commands don't produce
> complex solutions, e.g.
> '4*x^3+8*x-4' SOLVEVX
> gives an empty list.
>
> Am I doing something wrong? Does the CAS understand complex numbers?

As  you have entered it, your variable seems to be the lower case'x',
not the upper case 'X'.

The calculator is case sensitive, and the default variable for SOLVEVX
is an upper case 'X', not a lower case 'x'.
```
 0

```Virgil wrote:
> In article
> <1134924023.58fec87c58f249b740f40b921c33786d@roc.usenetexchange.com>,
>  Borris <none@none.com> wrote:
>
>
>>I've set the CAS to complex mode, but the symbolic commands don't produce
>>complex solutions, e.g.
>>'4*x^3+8*x-4' SOLVEVX
>>gives an empty list.
>>
>>Am I doing something wrong? Does the CAS understand complex numbers?
>
>
> As  you have entered it, your variable seems to be the lower case'x',
> not the upper case 'X'.
>
> The calculator is case sensitive, and the default variable for SOLVEVX
> is an upper case 'X', not a lower case 'x'.

Sorry, I used an upper X
```
 0

```Strange. When I do '4*X^3+8*X-4'  SOLVEVX (in complex mode, FIX 2) I
get:
{ X=(-0.23,-1.47) X=(-0.23,1.47) X=0.45 }

You might have a strange flag setting; do CASCFG and try again.

-Joe-

```
 0

```In article
<1134944856.efa44d290a5d4ace54b050d099bedb85@roc.usenetexchange.com>,
Borris <none@none.com> wrote:

> Virgil wrote:
> > In article
> > <1134924023.58fec87c58f249b740f40b921c33786d@roc.usenetexchange.com>,
> >  Borris <none@none.com> wrote:
> >
> >
> >>I've set the CAS to complex mode, but the symbolic commands don't produce
> >>complex solutions, e.g.
> >>'4*x^3+8*x-4' SOLVEVX
> >>gives an empty list.
> >>
> >>Am I doing something wrong? Does the CAS understand complex numbers?
> >
> >
> > As  you have entered it, your variable seems to be the lower case'x',
> > not the upper case 'X'.
> >
> > The calculator is case sensitive, and the default variable for SOLVEVX
> > is an upper case 'X', not a lower case 'x'.
>
> Sorry, I used an upper X

The HP calculators will not find exact irrational zeros to a cubic
polynomial, but can find approximate ones.

An alternate form for getting approximate zeros is to enter [ 4 0 8 -4]
as the vector of coefficients and then use the PROOT command to get a
vector of the zeros. This works regardless of flag settings.
```
 0

``` Set your calculator to approximate mode ,then using SOLVEVX  will give

```
 0

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7/25/2012 1:36:43 PM