Level Curves & Surfaces Flashcards
Level Curve
z = f(x,y) -> c = f(x,y)
a slice of a function
Open Disc
Point Pₒ = (xₒ, yₒ) in ℝ
disk = {(x,y) includes ℝ^2 | (x,y)^2 +(xₒ, yₒ)^2 < r^2}
Interior Point
A Point is an interior point if an open disc caintained in R exists
Interior Set
All interior points = Rₒ (but ₒ is above)
Open Set
if R = Rₒ
eg: x^2+y^2 < 9 (boundary not included)
Boundary Point
If an open disc around the point contains both R and not R
Boundary Set
∂R ( All boundary Points )
Closure of R
R_ (line above) = R ∪ ∂R
Closet Set
If R = R_
Bounded Set
If a disc around it can be drawn
eg. Rectangle or sphere
Unbounded
Strip around it can not be drawn
eg. Strip or half-plane
Compact Set
Bounded + Closed
If a disc around it can be drawn + R = R_
note: Compact always have a global max and min