HW5 problem 3.b

[questions?]

Thetaj has normal prior and multiple bernoulli likelihood, then the
function is the product of these two.
How to find quadratic function to approximate the log(gj) ,where the
bernoulli function is very annoying... ...
If we do taylor expansion, the terms get quite nasty... ...//Am I on
the wrong track?

Thanks

[Will Chang]

There is apparently a neat way to take the derivatives of these
sigmoid-bernoullis, as explained in Chapter 7 of the text.