Math Is Fun Forum

Dragonshade

Member

Registered: 2008-01-16

Posts: 147

Limite and proof

I tried to prove this, but it doesnt seem satisfying (The last step)

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Limite and proof

You’ve got all the required steps in your proof but you need to put the steps in the correct logical order.

Dragonshade

Member

Registered: 2008-01-16

Posts: 147

Re: Limite and proof

ok, what bothers me is that last step, It seems that I cant get x>N,  since (x-N)^2>0 , is valid for whaever value of x and N

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Limite and proof

Do you know what you are supposed to be doing?

You are supposed to show that given any ε > 0, there exists N such that

.

You have found your N:

You’re almost there. Now all you need to do is rewrite your steps in the correct logical order.

Dragonshade

Member

Registered: 2008-01-16

Posts: 147

Re: Limite and proof

Ah, I see, thx