Remarks
By
X
0
we mean 1.
We do not distinguish between the polynomials 0
X
k
and 0. Terms of the form 0
X
k
are often left out.
We usually write
X
k
instead of 1
X
k
and -
X
k
instead of (-1)
X
k
.
We reduce an expression like
X
2
+ (-4)
X
3
to
X
2
- 4
X
3
.
Clearly, the inclusions
Z
Q
R
imply the inclusions
Z
[
X
]
Q
[
X
]
R
[
X
].
`
X
' is not the exclusive name for an indeterminate. Other symbols that we will occasionally use are, for example,
Y
or
Z
.
The words polynomial and monomial are Greek: poly=many, mono=one, nomos=term, name.