Determine whether set is closed, open or neither.

[MechanicalBrank]

Homework Statement

D1 = {(x,y) : x^2 + y^2 < 3, x+2y = 2}
D2={(x,y) : x^2 + y^2 > 2}
D3={(x,y) : x + 2y = 2}

Homework Equations

The Attempt at a Solution

D1 is neither, D2 is open and D3 is closed, am I right or wrong?

 

[PeroK]

Right!