Question

What is open set, close set , neighborhood , bound , compact , and connected?
Let S={(x,y): -1 14 years ago

Answer 1

looks like open set ... -1<=x<=1, is a closed set, in both cases bound is -1 (greatest lower bound) and +1(smallest upper bound), all values beyond GLB and SUB is also a bound ..... if the set has finite number of sub cover ... it's called compact ==> that's all i studied ... but never understood clearly.

Answer 2

Dint understand anything :-( I looked for this ques 's ans , and its written dt its neither open nor closed :-((

Answer 3

If your set is in the plane. Then it is clearly bounded. It is not open since it cannot contains any disc. It is not closed. because \[x_n=1-\frac 1 n\] is a sequence in it that tens to 1 and 1 is not in the set. So it is not compact.

Answer 4

tends

Answer 5

I dont know anything about sequence , some odr way to explain plz ?

Answer 6

Do some reading about it.

Answer 7

See I have the ans but not able to understand , here it goes :
Its not open because a set of Z integers is nt open set , its not closed because R square -S is not open as (-1,0) has no disc centred at (-1,0) and contained in Rsquare - S !
now wt does ds mean ?

Answer 8

i myself seems not to understand it ... lol

Answer 9

yea its toooo tiring ! since morning ( in india ) , Iam doing ol ds stufff , bt no progress ! :<<<

Answer 10

Do some reading about open, closed sets in the plane.