MAT 3730 Complex Variables Section 1.6 Planar Sets http://myhome.spu.edu/lauw
Preview For real variables, theorems are typically stated for functions defined on intervals (open, closed) We will introduce the corresponding concepts in the complex plane Mostly the same as defined in R2 (MAT 3238?)
Definition 1 Open Disk/ (Circular) Neighborhood
Example 1
Definition 2 Interior Points
Example 2
Definition 3 Open Sets
Example 3
Example 4
Example 5
Definition 4 Connected Open Sets
Example 6
Example 7
Definition 5 Domain
Domain Many results in real and complex analysis are true only in domains. Below is an example in calculus (real analysis). We will take a look at why the connectedness is important.
Theorem Idea
Definition 6 Boundary Points
Observations
Definition 7 Boundary
Example 8
Example 8
Definition 8 Closed Sets
Example 9
Example 10
Example 10
Definition 9 Region
Definition 9 Region T or F: If D is a domain, then it is a region.
Definition 9 Region T or F: If D is a domain, then it is a region. T or F: If D is a region, then it is a domain.
Definition 10 Bounded Sets
Question Can you name a unbounded set?
Definitions Dependency nhood Interior Points Open Set Connected Set Domain Boundary Points Bounded Set Closed Set Region
Next Class Read Section 2.1 Review Onto Functions