One thing I learned this week was set notation and interval notation, some examples are.

when you use set notation with the domain, you use the greater/less then signs to show what space the domain covers on the x axis, in this example, x is less then 4 on the line so you can see that the domain is going to the left and since it does not state where x stops so it goes left forever until it reaches -∞. For interval notations, you first have to put a “D=” which stands for “domain”, when you look at it, it looks like a coordinate on a graph, but the brackets are what tells you everything, when the brackets are rounded it means that it is an open dot which means its not counted when you would do the numbers, if its a closed dot which means it can be applied to the numbers, you use [ ] brackets. Ex.

as you can see in this example, there is an closed dot which means the equation used squared and rounded brackets to express if its an open or closed dot.