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IsTim
Group Title
Find the equation of the tangent to the curve at the given x value.
 2 years ago
 2 years ago
IsTim Group Title
Find the equation of the tangent to the curve at the given x value.
 2 years ago
 2 years ago

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IsTim Group TitleBest ResponseYou've already chosen the best response.0
dw:1335261368315:dw
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
I got up to this:dw:1335261401688:dw
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
dw:1335261446849:dw
 2 years ago

chaise Group TitleBest ResponseYou've already chosen the best response.2
Calculate the derivative of the equation, make the equation to equal, solve it and plug in your x value. Are you familiar with the quotient rule in derivatives?
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Deriatives is f'(x) right? we're not doing that yet.
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Methods we're using is substitution, factoring and the conjugate method.
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
I'm using the Calculus Phobe videos from Calculus Help (my teacher showed me the website and told me to use that).
 2 years ago

chaise Group TitleBest ResponseYou've already chosen the best response.2
Yes, that's correct. So you're differentiating using the definition? If you take the derivative of the equation y=3/(x^21) you can find the slope. if: f(x)=3/(x^21) then f(x+h)=3/((x+h)^21) dy/dx = (f(x+h)f(x))/h Can you do the rest?
 2 years ago

chaise Group TitleBest ResponseYou've already chosen the best response.2
dy/dx =lim (h>0) (f(x+h)f(x))/h rather.
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Yes. That's what I did.
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
But I can't go any further. dw:1335262087563:dw That's the furthest I got up to.
 2 years ago

chaise Group TitleBest ResponseYou've already chosen the best response.2
Expand your brackets and factor out a h.
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
The bottom one to? I was told not too.
 2 years ago

chaise Group TitleBest ResponseYou've already chosen the best response.2
Not sure  I'm not familiar with the long method, I just use the shortcut :)
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
Can you take derivatives? Must you use first principle to find it?
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Derivatives is our next unit.
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
I can't isolate or factor out anything. I must had made a mistake beforehand I guess.
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
I hope you don't mind me posting my solution here
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
I guess not, but it's notm much like my work.
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
Oh shoot... I got some mistakes there! Wait
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
Once again :(
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
Oh my dear!!! The final answer should be 4/3 ... not 2 as I've written :S
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
Is your question \[\frac{3}{x^21}\] or \[\frac{3}{x^2+1}\]?
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Maybe I should upload my work, and maybe you check for problems?
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Starting from c) at Scan001.
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
f(a) is not 1
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
f(a) is 3/ (a^2 1)
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
but since x=2, I subbed in a=2 into that equation...
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
for the denominator, (a+h)a =h , not a+h 2 You need to find the limit before substituting the numbers.
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
After you've found the limit, you'll see the unknown x. By then, sub x=2 and you'll get the slope. But NOT when you're taking the limit
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
I thought the unknown to be m, and that h was still the variable withint the equation?
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
h is something you need to deal with. Should I upload an example to should how you do first principle for you ?
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
I've got an example here with me from my teacher.
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
If you don't need it, it's okay :) Should I keep checking for you or you want to do corrections first?
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
What should I correct?
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
Correct starting from the third line For numerator: a > 3/ (a^2 1) For denominator: a+h2 > h (in your previous step, a+h a, simplify it , you'll get h)
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Sorry if I sound ignorant, but that's how I saw it in the example...the h is alone.
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
Do you mind uploading your example also?
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
First, the situation is different . You're given 2 values there, but only 1 here. Second, to be frank, I don't understand what you (or your teacher) is doing. It's not the normal way as I've learnt.. Third, I still insist that you shouldn't sub the value immediately...
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Ok. I think I know what you are doing, and what my teacher is doing. You're going from a general formula, while my teacher is using the specific formula. The general formula doesn't sub in the x or a value until the end.
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.1
It's good that you notice the difference :)
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Just looking through my notes I guess. I've got a test coming up, so I thought reviewing would be best.
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
well, where do you need help with? This is pretty long..
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Maybe I should just leave this question. I tried this for over 2 hours by now.
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
First, what is the question? \[\frac{1}{x2} \]?? or \[\frac{3}{x^{2}1} \]??
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Second one, whereas x=2.
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Ok. Thanks for the attempt guys. I'll try other problems, and maybe this might make more sense.
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
wait..i will try and do it first.. can't you take the derivative which is easier?
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Others suggested that, but that's for the next unit. I understand a bit on how that works, but I'm not allowed using it here.
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
Hmm..I might try it but it might take a while since i havent done these in a while...
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Ok. Well, I guess you can do so, if yo uhave free time. But most likely you too have something important coming up (immediately).
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
No, I don't have anything important..i might be able to do it but not sure..lol
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
I have to review these anyway
 2 years ago

apoorvk Group TitleBest ResponseYou've already chosen the best response.0
^^That was mammoth. phew. Istim do you know how to differentiate using chain rule?
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
lol, i failed...do you remember how to do these apoor? my brain is failling me :(
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
No, I don't (Sorry, cleaning up house).
 2 years ago

apoorvk Group TitleBest ResponseYou've already chosen the best response.0
Hmm. so you want to do this by the first principle of finding derivatives okay.
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
I am just oh so selective in the method used. That be the end of me.
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
\[\large\frac{f(x+h)f(x)}{h} =>\frac{\frac{3}{(x+h)^{2}1}\frac{3}{x^{2}1}}{h} \]
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
right so far?
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
I have no idea.
 2 years ago

chaise Group TitleBest ResponseYou've already chosen the best response.2
should be the limit as h approaches zero, but, apart from that, correct. ^_^
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
\[\large =>\frac{\frac{3}{h^{2}+2hx+x^{2}1}\frac{3}{x^{2}1}}{h} \] \[\large >\frac{\frac{3(x^{2}1)3(h^{2}+2hx+x^{2}1)}{(h^{2}+2hx+x^{2}1)(x^{2}1)}}{h} \]
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
I think that im doing it wrong..i dont think that its this complicated..
 2 years ago

chaise Group TitleBest ResponseYou've already chosen the best response.2
Perhaps you should just use quotient rule.
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
but it says derivatiive thing is not allowed..
 2 years ago

IsTim Group TitleBest ResponseYou've already chosen the best response.0
Before using deratives. Referencing Calculus Phobe from Calculus Help. I think I used Conjugate Method.
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
whaat..im lost..i looked at your example but it got confusing..then i looked at my book its more confusing..using the chain rule is easier.
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.2
\[\frac{3}{x^{2}1} => 3(x^21)^{1}\] \[3(x^21)^{1}*2x \] \[6x(x^21)^{1}\] easier i suppose..
 2 years ago
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