<A NAME=FACTOR_declaration>
<TITLE>FACTOR_declaration</TITLE></A>
<b><a href=r37_idx.html>INDEX</a></b><p><p>
<B>FACTOR</B> _ _ _ _ _ _ _ _ _ _ _ _ <B>declaration</B><P>
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When a kernel is declared by <em>factor</em>, all terms involving fixed
powers of that kernel are printed as a product of the fixed powers and
the rest of the terms.
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syntax: </H3>
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<em>factor</em><kernel> {<em>,</em><kernel>}*
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<kernel> must be a
<A HREF=r37_0002.html>kernel</A> or a
<A HREF=r37_0053.html>list</A> of
<em>kernel</em>s.
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examples: </H3>
<P><PRE><TT>
a := (x + y + z)**2;
2 2 2
A := X + 2*X*Y + 2*X*Z + Y + 2*Y*Z + Z
factor y;
a;
2 2 2
Y + 2*Y*(X + Z) + X + 2*X*Z + Z
factor sin(x);
c := df(sin(x)**4*x**2*z,x);
4 3 2
C := 2*SIN(X) *X*Z + 4*SIN(X) *COS(X)*X *Z
remfac sin(x);
c;
3
2*SIN(X) *X*Z*(2*COS(X)*X + SIN(X))
</TT></PRE><P>Use the <em>factor</em> declaration to display variables of intere
st so that
you can see their powers more clearly, as shown in the example. Remove
this special treatment with the declaration
<A HREF=r37_0217.html>remfac</A>. The
<em>factor</em> declaration is only effective when the switch
<A HREF=r37_0319.html>pri</A>
is on.
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The <em>factor</em> declaration is not a factoring command; to factor
expressions use the
<A HREF=r37_0287.html>factor</A> switch or the
<A HREF=r37_0151.html>factorize</A> command.
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The <em>factor</em> declaration is helpful in such cases as Taylor polynomials
where the explicit powers of the variable are expected at the top level, not
buried in various factored forms.
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Note that <em>factor</em> does not affect the order of its arguments. You
should also use
<A HREF=r37_0212.html>order</A> if this is important.
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