Question

Lim of tan(x) as x approaches pi/2. It does not ask from either the + or - direction, just pi/2. The answer is 0, but i think it is DNE? Cause from the left, it is infinity and from the right, negative infinity

Answer 1

it DNE (actually it exists but is undefined. Because of exactly what you said. If the case were different, you could use the sandwich theorem to solve this.

Answer 2

there is a sandwich theorem???????????? O.o

Answer 3

lol also known as the squeeze theorem

Answer 4

Yes, it deals with collapsing things and looking at the resultants, yes. also known as squeeze theorem.

Answer 5

ok i dusy for ya, how about cos(1/x) as x approaches 0 (again no + or -), in this case it looks like insane scribbles around -1 to 1 so what to do? ?

Answer 6

Funny name lol :D

Answer 7

Ohhhhhh.....now i get wht it is.....In Albania it is called ''two cops' theorem''

Answer 8

lol, never heard it called that.

Answer 9

I had never heard it was called sandwich O.o

Answer 10

can u help on the last question though?

Answer 11

\[\lim_{x \rightarrow 0} Cos(1/x) = Undefined\]
left and right limits are undefined as well, lol

Answer 12

so DNE? but i just suddenly thought that you are supposed to like zoom in a lot on the calculator, but that seems to fade now, cause i am thinking when u get these scribbles, its just DNE?

Answer 13

It's because of the hole at 0
It goes up and down quicker as you approach 0 from left and right. Too fast to define, because it is escaping