MACRO calculating energy cost EC

[Aprillmylmy]

Dear developer,

I have a question about Equation COST_ENERGY in MACRO:

In the website, it mentioned using a quadratic second-order term as the Taylor expansion;

What I couldn't understand is if we need to introduce a factor of 1/2 in the quadratic form? As I understand Tylor expansion to be:

Taylor = f(a) + f'(a)(x-a) + 1/2 f"(a)(x-a)^2?

The reason for proposing this is that, I noticed, the quadratic term sometimes generates larger values than the linear term, which I think may be due to the "1/2" missing?

Thank you,
Emily