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alexthomas Group TitleBest ResponseYou've already chosen the best response.0
dw:1372210588807:dw
 one year ago

alexthomas Group TitleBest ResponseYou've already chosen the best response.0
the radical is over the (+x) as well if not clear
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
You want to multiply by the conjugate
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
\[\large \lim_{x \rightarrow \infty} \ \frac{\sqrt{25x^2+x}5x}{1} \cdot \frac{\sqrt{25x^2+x} +5x}{\sqrt{25x^2+x} +5x}\]
 one year ago

alexthomas Group TitleBest ResponseYou've already chosen the best response.0
i'm getting 25+x25x^2 /radical 25x^2+x +5x
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
\[\large \lim_{x \rightarrow \infty} \ \frac{(25x^2+x)(5x)^2}{\sqrt{25x^2+x} +5x} \]
 one year ago

alexthomas Group TitleBest ResponseYou've already chosen the best response.0
exactly
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
\[\large \lim_{x \rightarrow \infty} \ \frac{x}{\sqrt{25x^2+x} +5x}\]
 one year ago

alexthomas Group TitleBest ResponseYou've already chosen the best response.0
good i got that too it cant be simplified any further right?
 one year ago

dumbcow Group TitleBest ResponseYou've already chosen the best response.0
i would use l'hopitals rule now
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Ah. Okay.
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
LH Rule: \[\large \frac{ f'(x)}{g'(x)}\]
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Since if we took the limit to infinity we'd get \(\large \frac{\infty}{\infty}\)
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Can you tell me what the derivative of \(\large \sqrt{25x^2 +x} +5x\) is?
 one year ago

alexthomas Group TitleBest ResponseYou've already chosen the best response.0
dw:1372212305372:dw
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Not exactly.. We have \(\large \sqrt{25x^2+x}+5x\) right? That can be rewritten as \(\large (25x^2 +x)^{1/2}+5x\) Using chain rule: \(\large \frac{1}{2\sqrt{25x^2+x}} \cdot (50x +1) +5\) Simplify : \(\large \frac{50x+1}{2\sqrt{25x^2+x}} +5\)
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
So now we'll have... \[\huge \lim_{x \rightarrow \infty} \ \frac{\frac{1}{50x+1}}{2\sqrt{25x^2+x}+5}\]
 one year ago

alexthomas Group TitleBest ResponseYou've already chosen the best response.0
i got the answer to be 1/10 thank you
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Can you explain to me how you got that? :o
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
what i got was \[\large \lim_{x \rightarrow \infty} \ \frac{1}{(100x+2)(\sqrt{25x^2+x}+5)} = 0 \]
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
An unforseen method of approach!
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
dw:1372214578635:dw
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
what shud we subtract there
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Uhhh...
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
i dunno for some reason i feel like it cant be 0
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
dw:1372215149908:dw
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Hmmm...
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
1/10 is probably right
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
How do you factor out a 5x from \(\large \sqrt{25x^2+x}\) ?
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
its tough sqrt roots arent friendly
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
HOW DO YOU GET 1/10???? thats what i wanted to know! and then the guy disappeared lol.
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
gotta use other ways
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
i didnt im just saying that answer looks right lol
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
secret methods....hidden treasures.
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
I want toknow this.
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
maybe we can rewrite this as some other known function base like hyperbola?
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.2
dw:1372215364565:dw
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
what??...
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.2
dont need to use L'H,just put x in evidence
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
im so confused.....wait a minute...
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
shudda known it was something simple
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
basically hes saying the highest exponents there will just be root(25x^2) and 5x so we can still divide everything by x
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Oh...hm. Let me try this.
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.2
dw:1372215619036:dw
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
dw:1372215830146:dw
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
@whpalmer4 show us the way
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.2
dw:1372215784059:dw
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Am i wrong?
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.2
i think that is not right
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
u shud have +5 there instead of last 0, and ur diving by x that is the higest power
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Oh YEAH. 5x/x * my bad.
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
I forgot the x...... 1/10 is the answer,lol. whoops.
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.2
@dan815 x²(25+1/x)= 25x²+x
 one year ago

dan815 Group TitleBest ResponseYou've already chosen the best response.0
dw:1372216059586:dw
 one year ago

whpalmer4 Group TitleBest ResponseYou've already chosen the best response.1
you were on the right track \[\large \lim_{x \rightarrow \infty} \ \frac{x}{\sqrt{25x^2+x} +5x} = \large \lim_{x \rightarrow \infty} \ \frac{1}{\frac{\sqrt{25x^2+x} +5x}{x}}\]
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.2
dw:1372216149948:dw
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
\[\large \lim_{x \rightarrow \infty} \ \frac{x/x}{\sqrt{25x^2/x^2 +x/x^2}+5x/x}\]\[\large \frac{1}{\sqrt{25+0}+5} =\frac{1}{10} \]
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
When lim tends to infinity, divide by highest exponent. When lim tends to a number, use LH rule :D
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.2
just take care because if x goes to  inf x=x
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
yeah. I understand :)
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.2
sqrt(x²)=x not x; we do that only because we know x is positive(inf)
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
You divide everything under a square root by the highest power underneath the root, and all the other x's get divided by the value of x that is dependent on the behavior of the function, (i.e if x tends to positive or negative infinity)
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
lol we're saying the same thing....2 different ways :(
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.2
if x goes to  inf the result isn't the same
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
yes,so if x goes to inf, x takes on neg values.... hence we divide by x instead of x.
 one year ago

whpalmer4 Group TitleBest ResponseYou've already chosen the best response.1
\[\large \large \lim_{x \rightarrow \infty} \ \frac{1}{\frac{\sqrt{25x^2+x} +5x}{x}} = \frac{1}{5+ \sqrt{\lim_{x\rightarrow \infty} \ \frac{25x^2+x}{x^2}}} \]\[= \frac{1}{5+ \sqrt{\lim_{x\rightarrow \infty} \ \frac{50x+1}{2x}}}\]by L'Hopital \[=\frac{1}{5+\sqrt{25}}\]
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Oh, I see.
 one year ago

Jhannybean Group TitleBest ResponseYou've already chosen the best response.1
Tried @whpalmer4 's way myself just now. REALLY interesting hahaha
 one year ago
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