2.11 ( ) www By expressing the expectation of ln j under the Dirichlet distribution (2.38) as...

2.11 () www By expressing the expectation of ln μj under the Dirichlet distribution

(2.38) as a derivative with respect to αj , show that E[ln μj] = ψ(αj) − ψ(α0) (2.276)

where α0 is given by (2.39) and

ψ

(a) ≡ d da ln Γ

(a) (2.277)

is the digamma function.