I have a problem with my homework:

1. prove only by the defenition of the limit that

Thanks ahead

Printable View

- Apr 4th 2009, 01:54 AMomertHelp with limits
I have a problem with my homework:

1. prove only by the defenition of the limit that

Thanks ahead - Apr 4th 2009, 04:41 AMProve It
Are you allowed to use L'Hospital's Rule?

If so, it's very easy...

.

Without L'Hospital, not so easy...

All I can think of is the Sandwich Theorem, but I can't think of what to sandwich it inside.

I know that .

We just need to find something that is less than or equal to... - Apr 4th 2009, 04:46 AMmr fantastic
- Apr 4th 2009, 04:59 AMProve It
- Apr 4th 2009, 05:37 AMomert
I can't use any theorem. I need to prove it only by the defenition. let be M>0 so the any delta>0.... x-pi/2 -->>> 1/cosx<=M

thanks ahead - Apr 4th 2009, 05:38 AMProve It
- Apr 4th 2009, 07:06 AMmatheagle
You need to approach from the right and the left.

- Apr 4th 2009, 07:42 AMTwig
Like matheagle says, approach from left and right.

And from the left:

I hope this is correct.. - Apr 4th 2009, 07:54 AMmatheagle
- Apr 4th 2009, 07:57 AMTwig
oops yeah, thx (Cool)