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<A NAME=ChebyshevU>

<TITLE>ChebyshevU</TITLE></A>
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<B>CHEBYSHEVU</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
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The <em>ChebyshevU</em> operator returns the nth Chebyshev U Polynomial (of the 

second kind). 
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syntax: </H3>
<em>ChebyshevU</em>(&lt;integer&gt;,&lt;expression&gt;) 
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examples: </H3>
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ChebyshevU(3,xx); 

          2
  4*x*(2*x   - 1) 



ChebyshevU(3,4); 

  496

</TT></PRE><P>Chebyshev's U polynomials are computed using the recurrence relati
on: 
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ChebyshevU(n,x) := 2x*ChebyshevU(n-1,x) - ChebyshevU(n-2,x) with 
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ChebyshevU(0,x) := 0 and ChebyshevU(1,x) := 2x 
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