The monomials xj j greaterthanorequalto 0 can be expressed
     The monomials {x^j | j greaterthanorequalto 0 can be expressed as combinations of the Chebyshev polynomials. Easily, 1 = T_0(x) and x = T_1(x). Next, x^2 = 1/2 [T_2(x) + 1] = 1/2 T_2(x) + 1/2 T_0(x)  Proceeding similarly, express x^3 and x^4 as combinations of Chebyshev polynomials. 
  
  Solution
a)
T3=4x^3-3x=4x^3-3T1
4x^3=T3+3T1
x^3=(T3+3T1)/4
T4=8x^4-8x^2+1=8x^4-4(T2+T0)+T0
8x^4=T4+4T2+3T0
x^4=(T4+4T2+3T0)/8

