0
Still curious? Ask our experts.
Chat with our AI personalities
Coach
Rafa
MaxineAdd your answer:
Earn +20 pts
Mcdougal littel geometry 2004 book view online?
no
When was The Zenith Angle created?
The Zenith Angle was created in 2004-05.
When did Winning Lines end?
Winning Lines ended on 2004-10-16.
Is every point of an open set E contained in R2 a limit point of E?
In reply to "limit point", posted by Jennifer on Sept 24, 2004: >I have a basic question. Thanks a lot. > >Is every point of every open set E (is contained in R^2) a limit point of E? Yes, it is. If O is open and x is in O then some open ball B(x,e) is contained in O (as x is an interior point of O). But open balls in R^2 have the property that they contain many more points than just x (eg also (x_1 + 1/2*e, x_2) for x = (x_1, x_2), and e>0 ) and so if B(x,r) is any neighbourhood of x, then B(x, min(r,e)) will contain this point, which is in O (as B(x,e) \subset O) and not equal to x. So x is a limit point of O. >In case of for clsed sets in R^2? > There it fails, eg if C = {(1/n, 0): n in N}. No point of C is a limit point of C (but (0,0) is), as is easily checked. Henno
