Another Math Help Thread

[TigerHunter]

My math teacher won't help me, my classmates are clueless, and Google has failed me. So, I turn to you, internets! Save my Calculus grade! Show by means of an example that lim x->a (f(x) + g(x)) may exist even though neither lim x->a f(x) or lim x->a g(x) exists!

[averagejoe]

An easy way to do this is to take a function that has a non existent limit and simply take the negative. e.x., a=0, f(x)=1/x, g(x)=-1/x.

[TigerHunter]

An easy way to do this is to take a function that has a non existent limit and simply take the negative. e.x., a=0, f(x)=1/x, g(x)=-1/x.
...in retrospect, that is so incredibly easy that I'm ashamed of myself for not thinking of it earlier.

Thank you so much! Have a cookie.

http://pixiestixkidspix.files.wordpress.com/2007/08/cookie-bite-web.jpg

[averagejoe]

...in retrospect, that is so incredibly easy that I'm ashamed of myself for not thinking of it earlier.

Thank you so much! Have a cookie.

Well, it's easy to overlook, because no one really thinks of "zero" as a function. I actually remember stressing out about this question myself. I'm fairly certain that there are other ways to go about it, but they're too troublesome to think up.

On another note, cookies are delicious. :smallsmile: