This week brought back a concept that I had happily forgotten-- Sigma Notation. It is not necessarily a hard concept to learn, it has just always intimidated me, probably because in every movie ever sigma notation is used for "Hard Math Problems". Luckily, after a quick review I remember how easy it is. The entire notation is just shorthand for a bunch of addition. K is your starting term, n is your ending term, and a(k) is your function.
We went on this week to apply sigma notation to the rectangles we had used for estimation the area underneath curves. This is represented by really complex sigma notation that involves limits and changes of x in regards to k. Thankfully it can be shortened to a nice Integral.
a is the starting # (your k), b is the ending # (your n), f(x) is the integrand of the function, and dx is the variable of integration. As long as your variable is constant you are ok, so theoretically you could use cats, but that would be way too much work. The entire thing reads as "the integral of f(x) from a to ". It's a nice concept that I am enjoying learning about.