In a GLM, suppose that var(Y) = () for = E(Y). Show that the link g

In a GLM, suppose that var(Y) = υ(µ) for µ = E(Y). Show that the link g satisfying g’(µ.) = [υ(µ)]^–1/2 has the same weight matrix W^(t) at each cycle. Show this link for a Poisson random component is g(µ) = 2√µ.