23-10-2016, 12:52 PM

Hello everyone,

since I come from Germany, my English isn't perfect. Sorry for that!

I just encountered the following Problem:

I wanted the HP Prime to calculate the roots (is it the right english word? the values of x_0 for which f(x_0) = 0) of

f(x) = x^4 - 3x^3 - 2.75x² + 12x - 5

which are 2.5, -2, 2, and 0.5.

In the CAS mode, I entered

zeros(x^4 - 3x^3 - 2.75x² + 12x - 5)

an got the Output

[2.5 2. -2. 0]

0 is obviously not a root of this polynomial.

Where is the mistake? On my side (and which one?) or on the HP Prime's side (and can it be fixed?)?

I would like to tell you my HP Prime's software version but I don't know how to find it out. Can someone tell me?

I have the same problem when I use the HP Prime Virtual Calculator on my Computer (the 2016_08_29 version).

Thank you for your answers!

Martin

since I come from Germany, my English isn't perfect. Sorry for that!

I just encountered the following Problem:

I wanted the HP Prime to calculate the roots (is it the right english word? the values of x_0 for which f(x_0) = 0) of

f(x) = x^4 - 3x^3 - 2.75x² + 12x - 5

which are 2.5, -2, 2, and 0.5.

In the CAS mode, I entered

zeros(x^4 - 3x^3 - 2.75x² + 12x - 5)

an got the Output

[2.5 2. -2. 0]

0 is obviously not a root of this polynomial.

Where is the mistake? On my side (and which one?) or on the HP Prime's side (and can it be fixed?)?

I would like to tell you my HP Prime's software version but I don't know how to find it out. Can someone tell me?

I have the same problem when I use the HP Prime Virtual Calculator on my Computer (the 2016_08_29 version).

Thank you for your answers!

Martin