gfun
algfuntoalgeq
find a polynomial equation satisfied by an algebraic function
Calling Sequence
Parameters
Description
Examples
algfuntoalgeq(expr, y(z), ini, typ)
expr
-
algebraic or radical function in z
y
name; holonomic function name
z
name; variable of the holonomic function y
ini
(optional) set; specify initial conditions for the resulting polynomial equation
typ
(optional) 'algebraic' or 'rational'; specify the type of coefficients for the polynomial equation
The algfuntoalgeq(expr, y(z)) command returns a polynomial in y and z that has expr as a root. The polynomial is not necessarily minimal.
If ini is specified, it is assigned a set of initial conditions for the polynomial to specify which branch is indicated (if possible).
If typ is specified as 'rational', the coefficients of the polynomial are of type rational or type name. This is particularly useful for finding a polynomial for an algebraic number. The default is 'rational'.
If typ is specified as 'algebraic' the coefficients are algebraic numbers. This option can be used with algebraicsubs.
with⁡gfun:
algfuntoalgeq⁡a⁢RootOf⁡_Z5+1⁢x23,y⁡x
a15⁢x10+y15
algfuntoalgeq⁡a⁢RootOf⁡_Z5+1⁢x23,y⁡x,algebraic
RootOf⁡_Z5+13⁢a3⁢x2−y3
algfuntoalgeq⁡513+3⁢723,y⁡x
y9−3984⁢y6+5112147⁢y3−2342039552
algfuntoalgeq⁡1+RootOf⁡_Z3+1⁢x,y⁡x,ini
−x3−y3+3⁢y2−3⁢y+1
y⁡0=1,D⁡y⁡0=RootOf⁡_Z3+1,D2⁡y⁡0=0
See Also
gfun/parameters
gfun[algebraicsubs]
RootOf
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