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swin2013 Group TitleBest ResponseYou've already chosen the best response.1
\[\lim_{x \rightarrow 3^{+}} 1/x+3\]
 2 years ago

across Group TitleBest ResponseYou've already chosen the best response.1
You have that\[\lim_{x\to3^+}\frac1{x+3}.\]Immediate substitution yields a division by zero. Therefore, you must have a vertical asymptote there. Approaching it from the right side, however, will yield \(\infty\) as the limit. On the other hand, approaching it from the left side will yield \(\infty\) as the limit.
 2 years ago

ksaimouli Group TitleBest ResponseYou've already chosen the best response.1
i am soory i read it wrong
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
since it is on the right side, do i write that the limit is approaching positive infinity?
 2 years ago

ksaimouli Group TitleBest ResponseYou've already chosen the best response.1
actually the limit DNE because the absolute value get very large
 2 years ago

across Group TitleBest ResponseYou've already chosen the best response.1
Because it's a sided limit, you have to specify \(\text{where}\) it goes. Simply writing DNE won't suffice.
 2 years ago

viniterranova Group TitleBest ResponseYou've already chosen the best response.0
I got it 1/6. Just plug it into the equation
 2 years ago

across Group TitleBest ResponseYou've already chosen the best response.1
@viniterranova, how did you get \(1/6\)?
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
I'm pretty sure i should get either  infinity or positive. I'm kind of unclear on what to write. I understand that when i divide the constant (1) by x2 (which is a small positive number), does that mean it's approaching positive infinity since 1 / x2 is getting positively bigger?
 2 years ago

viniterranova Group TitleBest ResponseYou've already chosen the best response.0
http://www.wolframalpha.com/input/?i=limit+x%3E+3%2B+%281%2F%28x%2B3%29
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
@viniterranova it's actually negative 3. it appears that the equation plugged in 3. if we plug in the value of 3, we get 0 on the denominator which is not valid since the denominator can't be zero
 2 years ago

across Group TitleBest ResponseYou've already chosen the best response.1
@swin2013, when you're asked to compute\[\lim_{x\to3^+}\frac1{x+3},\]if you substitute the limit, \(3\), you'll have that\[\frac1{x+3}=\frac1{(3)+3}=\frac10.\]Therefore, you know that the limit DNE. However, if you approach \(3\) from the right side, you'll have that\[\frac1{x+3}\]gets infinitely larger (since you're dividing by a really small number) toward \(\infty\). Oh, and @viniterranova, the limit is \(3\), not \(3\). Read the question again.
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
so am i correct in the sense that x  infinity?
 2 years ago

viniterranova Group TitleBest ResponseYou've already chosen the best response.0
See teh wolfram site.
 2 years ago

viniterranova Group TitleBest ResponseYou've already chosen the best response.0
The fact of you have the minus sign after 3 doesn´t mean that the 3 is negative. Just mean that you are approaching from left.
 2 years ago

viniterranova Group TitleBest ResponseYou've already chosen the best response.0
Just this.
 2 years ago

across Group TitleBest ResponseYou've already chosen the best response.1
No, you silly, \(3\) is different from \(3^\).
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
no. if it's approaching 3 to the left, there will be a negative as an exponent
 2 years ago

across Group TitleBest ResponseYou've already chosen the best response.1
@swin2013, for example, let \(k=2.99999\) be that close to \(3\). Then\[\frac1{k+3}=\frac1{2.99999+3}=\frac1{0.00001}=100,000.\]So you indeed approach \(\infty\).
 2 years ago

across Group TitleBest ResponseYou've already chosen the best response.1
(Notice that we're close to it from the right side.)
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
thank you @across, i just need clarity on what to write for my answer haha. I already understand the concept :)
 2 years ago

viniterranova Group TitleBest ResponseYou've already chosen the best response.0
Across you didn´t understand me. I just said minus sign after 3 not before.
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
yea but the equation never stated a negative sign after the 3.
 2 years ago

across Group TitleBest ResponseYou've already chosen the best response.1
That doesn't change the fact that you screwed up, @viniterranova. ;) @swin2013, you can write: "The limit does not exist as it approaches positive infinity."
 2 years ago

across Group TitleBest ResponseYou've already chosen the best response.1
You can also just write\[\lim_{x\to3^+}\frac1{x+3}=\infty.\]It depends on your teacher.
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
x  infinity no finite lim :)
 2 years ago

ksaimouli Group TitleBest ResponseYou've already chosen the best response.1
the correct way to say according to textbook is it DNE
 2 years ago

across Group TitleBest ResponseYou've already chosen the best response.1
lol @ksaimouli, you are right, but this is a SIDED LIMIT. In other words, YOU MUST SPECIFY WHERE IT IS GOING. <:)
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
lol i never said INFINITE i said FINITE
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
which is the same as DNE as in there is not possible limit
 2 years ago

swin2013 Group TitleBest ResponseYou've already chosen the best response.1
or DEFINITE limit (the derivative of FINITE)
 2 years ago
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