If i calculate (x^3+x):(x^2+3) manually via polynomial long division the result is x-(2x)/(x^2+3)
How can i get this result with the HP Prime?
Quote:
If i calculate (x^3+x):(x^2+3) manually via polynomial long division the result is x-(2x)/(x^2+3)
How can i get this result with the HP Prime?
In CAS mode, use partfrac. Access: Toolbox, CAS, 1. Algebra, 6. Partial Fraction
Hope that helps.
A further question: What is the difference between partfrac and cpartfrac?
Quote:
A further question: What is the difference between partfrac and cpartfrac?
cpartfrac is the complex counterpart of partfrac
Example:
cpartfrac((x^3+x)/(x^2+3)) returns x - 1/(x+i*sqrt(3)) - 1/(x-i*sqrt(3))
Thanks. Does CAS Settings / Simplify need to be set to NONE or MINIMUM for this result? Appears that MAXIMUM will show the rational being "recomposed" as x^3+x : x^2+3.
Best
Yes, it will recombine them in your version unforuntately. Note that this will all work much better in the future. There is a reason we did not put it to anything but "none" by default in the initial release. :-)
TW
Hi Tim,
A related issue. I want to expand and then recombine a symbolic polynomial to group the coefficients by powers, i.e.
(a-x)*(b-x) ---> a*b - (a+b)*x + x^2
If I enter this expression in CAS with simplify set to maximum in the settings the result I get is:
a*b - a*x - b*x + x^2
where the coefficients are not grouped for the power of x^1.
Is there some way to do this ?
Quote:
In CAS mode, use partfrac.
To see the results of polynomial long division, propfrac is more what he was looking for.
partfrac(((x^3+2*x²+3*x+4)/(x²-9))) returns the partial fractions
x+2+(29/3/(x-3))+7/3/(x+3)
while
propfrac(((x^3+2*x²+3*x+4)/(x²-9))) returns the proper fraction:
x+2+(12*x+22)/(x²-9)
-wes
I found a solution in the CAS function "symb2poly".
symb2poly ((a-x)*(b-x)) ---> [1 -a-b a*b]
real collect
Poly:= (a-x)*(b-x)
Var:= x
sum( coeff( Poly, Var ) .* seq( Var^k, k, degree( Poly, Var ), 0, 1 )
"propfrac" is exactly the command i need. It's too bad that "propfrac" is not in CAS-Menü.
quo, rem and quorem are the CAS instructions to perform polynomial division.