Squaring the Binomial

[MullenJohn]

Help,

Using my HP Prime calculator I am try to square the binomial (12*c^4 + 0.25*a^6*c)^2.

I was expecting something like (a^2 + B^2 + c) but I am getting only a number like 2.9887...

Please tell me how to expand the binomial with just the literals.

Thanks - Cheers!

[Joe Horn]

(05-22-2021 03:54 PM)MullenJohn Wrote:  Help,

Using my HP Prime calculator I am try to square the binomial (12*c^4 + 0.25*a^6*c)^2.

I was expecting something like (a^2 + B^2 + c) but I am getting only a number like 2.9887...

Please tell me how to expand the binomial with just the literals.

Thanks - Cheers!

Your variables might have values assigned to them. Purging them will force Prime to use them symbolically. Try purge(c) or del(c), and then try your simplification again.

Suggestion: Any time CAS sees a decimal point, it flips from "Exact" mode into "Approximate" mode. To use CAS to its full potential, avoid including any decimal points in CAS. E.g. use 1/4 instead of 0.25.

[Albert Chan]

Instead of purging variables, we can quote them. (quote(expr) == 'expr')
Quoting returns its argument unevaluated.

Cas> a:=b:=c:=1
Cas> expand('(12*c^4 + 1/4*a^6*c)^2')

1/16*a^12*c^2+6*a^6*c^5+144*c^8

---

BUG report: sometimes quoting does not work.
HP Prime emulator 2.1.14181 (2018 10 16):

Cas> expand('(12*c^4 + 1/4*a^6*c)^2')

150.0625

Not only quote not working, results somehow turned approximate.