Reading set notation
So I’ve been skipping my World of Warcraft time and reviewing calculus and differential equations so I don’t get too rusty. I almost immediately ran into an issue “reading” some of the set notation. It’s great because it’s compact and can communicate a lot of information but that doesn’t help if you can’t read it.
Take for example
{(x,f(x))|x∈A}
Doesn’t say much unless you can read it as “the set of all ordered pair x, f of x such that x is a member of set A”. Here are a few quick rules:
{ } denotes the set
( ) denotes and ordered pair
| “such that”
: also “such that” just in case things were too clear
∈ “is a member of”
∉ “is not a member of”
∪ union of two sets
∩ intersection of sets
So ℕ = {|a| : a ∈ ℤ} reads as “The set of natural numbers is equal to the absolute value of a such that a is a member of set ℤ”. Since ℤ is generally the set of ingeters { … ,-2, -1, 0, 1, 2, … } this means that ℕ = {0, 1, 2, … }
So now I can mostly read set notation again. Now I just need to learn MathML.
Boring but studies have shown that keeping a food log reduces snacking and binge eating simply because you’re more aware of what you’re eating and when.
Emily tested for her senior yellow today. She’s very enthusiastic but I need to spend more time working with her out of class on both her forms and the curriculum. I’m so proud of her. She has great enthusiasm and want her to build that pattern of success that will carry her forward in life.