For a degree-n homogeneous polynomial in two variables P(u,v)=x_0*u^n + x_1*u^(n-1)*v + ... + x_n*v^n, we consider the substitution w = a*u + b*v, z=c*u + d*v, where a, b, c, d are entries of some U in SU(2). The coefficients of the polynomial P(w, z) = y_0*u^n + ... + y_n*v^n can be obtained from x_0, ..., x_n under a linear transformation, represented by a matrix M(U; n). I will give an explicit formula for its entries, as well as give a 3-variable generating function for the entries in the case when U is the Hadamard matrix. M(U; n) is closely related to rotation matrices in the standard treatment of angular momentum in quantum mechanics.