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/sci/ - Science & Math

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4724082 No.4724082 [Reply] [Original]

Hi everyone. I was hoping one of you could give me some insight as to how to approach this problem. I usually handle integration of polynomials with the partial-fractions method, but for obvious reasons, this problem cannot be solved with that. I'm not asking for an answer; I'd just like to know where to begin.

Thanks in advance.

>> No.4724099

complete square on denominator

use inverse trig tan integral

>> No.4724100

>>4724082
>for obvious reasons, this problem cannot be solved with that.
It can...

>> No.4724108

Complete the square.

>> No.4724112

x^2+x+1=(x+1/2)^2+3/4

>> No.4724118

>>4724100
The polynomial cannot be factored, so in the end, the method would leave me with the same integration problem. If you argue that I could factor out x to get the denominator x(x+1+1/x)), this is true, but irrelevant, as it would leave me unable to find the B value.

>> No.4724124

>>4724118
stfu. All polynomials can be factored.

>> No.4724126

>>4724099
d/dx of arctan x = 1/(x^2 + 1). Although this technique may be useful it does not work here, sorry. Try x = tan u that might simplify things

>> No.4724136

>>4724118
All polynomials can be factored in a product of linear polynomials.
http://en.wikipedia.org/wiki/Fundamental_theorem_of_algebra

>> No.4724137

>>4724124
Technically this is true, but I don't think you appreciate how the partial-fractions method works. If you have any relevant input, I'd like to hear it, but right now it seems like you know even less than me about this sort of problem.

>> No.4724148

>>4724126
of course it will work derp

complete square to get 1/[(x+1/2)^2 + 3/4] = 4/3/[4/3(x+1/2)^2 + 1]

use sub sqrt(3)/2 (x+1/2) = tan u

herpity derpity

>> No.4724151

Completing the square results in imaginary numbers, so I don't think it's correct. Thanks for the help everyone, but I don't think I'll get any useful input from here.

>> No.4724155

>>4724148
sorry

*2/sqrt3 (x+1) = tan u

>> No.4724160

>>4724151
you are a fucking retard

this is the standard technique

see
>>4724148
>>4724155

>> No.4724170

>>4724151
>OP gets correct method in first reply. and third. and forth
>Ignores it

>> No.4724171

>>4724160
Do you even know what you're copy-pasting? No, it does not work. I don't want your "help," so go about your day.

>> No.4724179

>>4724171
Is this a troll?

Seriously, Completing the square and then using inverse trig is how this is done. Taught in Calc II.

>> No.4724190

>>4724171
oh fuck you

i sincerely tried to help. but you are just too weird

you don't have to solve the completing the square, so you don't get complex numbers. it just puts it in a form that looks like the standard inverse trig integral form, with an easy substitution

pretty sure wolfram show steps will convince you

then you can get your head out your ass and apologize to those that tried to help you

>> No.4724196

>>4724171
http://www.wolframalpha.com/input/?i=Integrate+1%2F%28x^2+%2B+x+%2B+1%29

and press show steps

you will see pretty much what the tripfag posted here

>>4724155
>>4724148

>> No.4724206
File: 31 KB, 590x699, OP is faggot.jpg [View same] [iqdb] [saucenao] [google]
4724206

>OP told to complete the square and use inverse tan
>for some reason doesn't

pic related

>> No.4724213

all my rage

>> No.4724224

Non-native english speaker here. What does complete the square mean?

>> No.4724236

actually you can still partial them, just need to deal with complex number

>> No.4724235 [DELETED] 

>>4724224
writing

x^2 + 4 + 7 = (x+2)^2 + 3

is an example of completing the square

>> No.4724257

>>4724236
that would be unnecessarily painful

>> No.4724261

>>4724235
I see. Thanks. Oddly enough I hadn't come across with this process.

>> No.4724274

>>4724148

>Act like an eleven year old playing a shitty pay-to-play MMOFPS
>"Why aren't you listening to me?"

>> No.4724282

>>4724274
well it is frustrating to offer correct help and be ignored

>> No.4724292

>>4724136
Yes, but there is no mechanical method to solving for the roots of a 5th degree polynomial or higher. Not applicable in the OP's case, but possibly relevant depending exactly on how you interpret:
>>4724124

>> No.4724296

>>4724282
Also, good work.

>> No.4724350

>>4724282

He didn't ignore you, he disagreed with you. Learn the difference.

>> No.4724354

>>4724350
whichever, he was wrong to do so

>> No.4724359

>>4724350
ignoring advice is pretty much synonymous with disagreeing with it.

>> No.4724360

>>4724354

no, he was incorrect.

Malice is to be responded to in your manner, but he just made a mistake. He even apologized for the contradiction, if you read more carefully!

>> No.4724364

>>4724360
Quit samefagging OP. If you don't like the rough and tumble of /sci/ then gtfo.

I told you the first step you wanted here.

>>4724112

And you derped like a faggot.

>> No.4724370

>>4724360
OP you came across like an arrogant fuck and deserved all the malice you got.

>> No.4724372

>>4724364

Thanks for the compliment, but I'm not the OP, although it is less believable that somebody else would be annoyed by fag's hubris. If I were the OP, that reference to MMOFPS's would have been made immediately.

>> No.4724375

>>4724372
OP samefag is samefag

>> No.4724380

>>4724372
It is not hubris to try and help and be rebuffed and get frustrated. I don't think you know what that word means.

Are you just butt hurt and passive aggressive because you got things wrong OP?

>> No.4724381

>>4724375

dude, you're in a thread you were never originally a part of implicitly defending somebody else as well.

Anyway, the OP is gone anyway, and I guess i'll run into fag sometime else.

>> No.4724385

>>4724381
i posted a hint way at the start of thread

>> No.4724391

>>4724381
If you aren't OP, aren't you also in a thread you were never a part of, implicitly defending someone?

Sure smells of samefag.

>> No.4724392

>>4724380

>It is not hubris to try and help and be rebuffed and get frustrated.

I'm going to have to stop you right there. Hubris involves a great deal of pride, certainly the kind that gets wounded when somebody disagrees with you and warps it into being ignored. i'm guessing IRL this sort of thing happens to you and you can no longer tell the difference?

>Are you just butt hurt and passive aggressive because you got things wrong OP?

i'm not even the OP! You just latched onto the idea after the other idiot suggested it!

>> No.4724396
File: 34 KB, 590x699, 1338157928733.jpg [View same] [iqdb] [saucenao] [google]
4724396

>>4724206
How do you go from there to there?
What rule is it using?

>> No.4724402

>>4724391

Yes, yes I am doing that. I was just using you as a case of how such a thing was possible.

Sageing for stagnant thread.

>> No.4724404

>>4724392
my pride has never been hurt, if i had pride i'd have left this thread ages ago.

i was hurt, as helping and being ignored hurts, but this has nothing to do with pride.

and you are clearly OP

>> No.4724406

>>4724396
i would tell you, but you wouldn't believe me

>> No.4724411

>>4724406
You can tell me. I'm not OP

>> No.4724414

>>4724402
except i was in this thread here 5th post >4724112

>> No.4724418 [DELETED] 

>>4724411
no, i'm just too proud. but i posted here the sub you need >>4724148
>>4724155

>> No.4724420

>>4724404

>Clearly OP
Think what you want, you seem hellbent on the idea that the more I provide reasonable arguments to the contrary, the more you must be right.

As for pride, you're just playing with semantics. Somebody politely disagreed with you, and in the biggest example of self entitlement I've seen all day, threw a tantrum about it, because somehow the world is being unfair to you for not being unrealistically virtuous or something?

>> No.4724423

>>4724396
Primitive of 1/(u²+a²) = (1/a)*arctan(u/a)

Or you can manipulate 1/(u²+a²) to get it in the form 1/(v²+1) like fag did and you'll get the same result

>> No.4724427

>>4724423
More like (1/a²)/(v²+1)

>> No.4724432

>>4724423
>>4724427
thanks

>> No.4724435

>>4724414

That wasn't you. The only reason to say that it was you is because your interest is served if I believe it, so I won't.

>> No.4724434

>>4724420
If you think using words correctly is just playing with semantics then derp.

I was, and am, childish, I don't mind, but I am not very proud. And it's not especially entitlement, it's, idk, my petulance?

And there are no reasonable arguments to prove against samefaggery on 4chan. It is impossible to counter. However the more the accused provides is the more likley the samefaggery, is the usual interpretation.

>> No.4724437

>>4724434

I made that accusation because you were ignoring the spirit of what I was saying in favor of the letter.

>> No.4724444
File: 49 KB, 520x342, ostrich-head-in-sand.jpg [View same] [iqdb] [saucenao] [google]
4724444

>>4724435
well this is fun

>> No.4724449

>>4724437
no, you just derped, twice, and that makes you as sore as being ignored makes me sore, but you need to retain some silly patina of adulthood.

>> No.4724453

>>4724437
>>4724435
>>4724420
>>4724402
Writing style is clearly OP's

>> No.4724456

>>4724449

>makes me as sore as

Wishful thinking. It's all too easy to look at somebody else's post and pattern match what you wish they are feeling instead of their real feelings.

Look, I actually have to go, but before I do, I want to know. Did you spend this whole thread thinking "I may be childish, but at least I'm not prideful like this guy is saying!"

>> No.4724461

>>4724456
>It's all too easy to look at somebody else's post and pattern match what you wish they are feeling instead of their real feelings.
physician heal thyself.

>Did you spend this whole thread thinking "I may be childish, but at least I'm not prideful like this guy is saying!"
oh the irony

>> No.4724463

>>4724456
exactly that OP

>> No.4724464

>>4724461

Well did you? Quickly, I'd like to be gone by 20:00

>> No.4724468

>>4724464
did i what?

>> No.4724471

>>4724463

figures, as long as you don't fit my exact description, any embarrassment or wrongness can be deflected by you.

>> No.4724474

>>4724224
Completing the square is expressing something that can't be simplified to <span class="math">(x+c)^2 in the form of (x+c)^2 +k

e.g.<span class="math"> x^2+2x+2 = (x+1)^2+1[/spoiler][/spoiler]

>> No.4724475

>>4724464
>leaving the house

I don't think so Tim.

>> No.4724476

>>4724471
yes, i'm going to cry tears now, and wish i was as great as you are

>> No.4724479

>>4724476

You stop caring when it's inconvenient for you.

>> No.4724480

>>4724471
>wrongness

are you still mad because you got math help and derped about it?

>> No.4724483

>>4724479
how much do you imagine i do care?

>> No.4724485

>>4724479
i think you mean convenient

>> No.4724489

>>4724483

>you are a fucking retard
>be rebuffed and get frustrated.
>herpity derpity

Lots, when it was convenient for you. Now you're playing non-nonchalance.

Shit, g2g.

>> No.4724493

>>4724489
bye bye OP

>> No.4724500

>>4724151
Your "imaginary" numbers, we call them complex numbers. And they won't magically destroy your integral, or whatever you "think" it would do.

>> No.4724502

>>4724489
And you aren't?

Going by post count, you both care equally, but you are better at disguising it.

>> No.4724515 [DELETED] 

4/3arctan(4/3(x+1/2))+c


complete the square you lazy fuck