polylib::elemSym
-- elementary
symmetric polynomialspolylib::elemSym
([x1,...,xn], k)
returns
the k
-th elementary symmetric polynomial in the given
variables x1
through xn
.
polylib::elemSym(l, k)
l |
- | list of indeterminatess |
k |
- | positive integer |
The result is a polynomial over the coefficient ring Expr
. If k
is greater than
the number of operands of l
, undefined
is returned.
l
is a valid first argument only if its
elements can be used as indeterminates of a polynomial .The first elementary symmetric polynomial is just the sum of its variables:
>> polylib::elemSym([x,y,z], 1);
poly(x + y + z, [x, y, z])
Indeterminates may also be e.g. trigonometric functions:
>> polylib::elemSym([sin(u),cos(u), exp(u)], 2);
poly(sin(u) cos(u) + sin(u) exp(u) + cos(u) exp(u), [sin(u), cos(u), exp(u)])