The Chebyshev polynomial of degree n is characterized by the property
.  The first six polynomials with their corresponding multiple-angle formulas are



Polynomial
Multiple-angle formula


         When n is small, the Chebyshev polynomials can be computed by using the recurrence
                                        
The formula can be obtained by using the formula for the sum of cosines
.

          Chebyshev polynomials are Lissajous curves.  Indeed, a parametrisation of the curve
 for  is x = cos t, y = -sin(t - p/2), 0 < t < 2p.

Chebyshev polynomials have the property
                                        
.       (2)

To see this when  

         

The proof is similar when n is odd.

            

Lissajous Figures and Chebyshev Polynomials
Julio Castiņeira Merino

Copyright the Mathematical Association
of America 2003. All rigths reserved