# New to Calculus, need help with Limits from Graphs

• Sep 26th 2009, 06:12 PM
Forum_User
New to Calculus, need help with Limits from Graphs
I have a math problem I need help with. I tried to do it but I wasn't really sure on any of them, and the last two (d and e) I have no idea how to do.

Question: Which of the following statements about the function y = f(x) graphed here are true and which are false?

Picture of the graph in the textbook(I recreated it as best as I could using Microsoft Paint):
http://img42.imageshack.us/img42/8564/90079656.jpg
a. lim f(x) does not exist.
x->2

My answer for a: False? I wrote "because it does not matter whether or not if the "circle" is shaded in". There is a line going over the part at 2, so I guess it does exist as x-> 2?

b. lim f(x) = 2
x->2

c. lim f(x) does not exist
x->1

My answer for c: false? The dot is there at 1 so it's false?

d. lim f(x) exists at every point x0 in (-1, 1).
x->x0(x over 0)

My answer for d: I don't understand the question or how to do this

e. lim f(x) exists at every point x0 in (1, 3).
x-> x0(x over 0)

My answer for e: Same as d, don't know.

Any help will be appreciated it, thanks in advance.
• Sep 26th 2009, 08:00 PM
superdude
For part b the statement is false, because the graph is defiantly not near y=2.

Part a the limit may be 1, but I'm not sure as it's been a long time since I've done any of these questions. I say this because as x approaches 1 from the left and right, the function appears to go to 1.

I don't understand questions d and e either, what do you mean by the "(over zero)" thing?
• Sep 27th 2009, 01:12 PM
Forum_User
Thanks for the reply. For d and e, here are the questions for d and e again, they look kind of like this in the text book.

d. lim f(x) exists at every point x0 in (-1, 1).
http://img524.imageshack.us/img524/9...thproblemb.jpg
My answer for d: I don't understand the question or how to do this

e. lim f(x) exists at every point x0 in (1, 3).
http://img524.imageshack.us/img524/9...thproblemb.jpg
My answer for e: Same as d, don't know.
• Sep 27th 2009, 02:19 PM
superdude
I've never heard a question asked this way but what I think it's asking is that "is x continuous as it approaches any of the numbers from 1 to 3" (or whatever the range).

So for d and e no x's isn't continuos because for (-1,1) there is a kink at x=0 and for (1,3) there is a jump discontinuity at 2