Avicus Archive

Some math help needed! by KenjiKido March 30, 2015 at 9:03 PM UTC

So I just finished AP calculus AB and BC. Now I'm doing integral calculus.
I think my teacher gave me this problem from the internet because I found it on the internet. I know the answer, but don't get it.
Could someone help me?

What is the integral of (X+1) / (X^2+2X) dX from 0 to 1?

Jahaj March 30, 2015 at 9:03 PM UTC

What's an integral?

MLGtino March 30, 2015 at 9:03 PM UTC

What's a math?

KenjiKido March 30, 2015 at 9:03 PM UTC

Google definition:
  1. An integral is a mathematical object that can be interpreted as an area or a generalization of area. Integrals, together with derivatives, are the fundamental objects of calculus. Other words for integral include antiderivative and primitive.

Jahaj March 30, 2015 at 9:03 PM UTC

Google definition:
  1. An integral is a mathematical object that can be interpreted as an area or a generalization of area. Integrals, together with derivatives, are the fundamental objects of calculus. Other words for integral include antiderivative and primitive.
O_O I'll read this post in a few years and I'll be so amazed at how I didn't know what an integral is. Can't help here sorry.

resepignev March 30, 2015 at 9:03 PM UTC

Ewww screw that! be a stripper!

Hacktivism March 30, 2015 at 9:03 PM UTC

/summon Milki

TheColdCrafter March 30, 2015 at 10:03 PM UTC

/summon Math

Rainstruck March 30, 2015 at 10:03 PM UTC

So first you can think of the integral as (x+1) * (x^2 +2x) ^-1 . next you will want to find the anti-derivative of both of those equations. So the AD (anti-derivative) of the first equation is x^2/2 +x. And the AD of the second equation is 1 because anything to the 0 power is 1. So the equation is x^2/2 *1. Hopefully that helps you out a little bit :]

voidloop March 30, 2015 at 10:03 PM UTC

Oh, really. I have been for 30 mins resolving D;, and now Rile comes D:

Rainstruck March 30, 2015 at 10:03 PM UTC

Lol!

voidloop March 30, 2015 at 10:03 PM UTC

xD.

KenjiKido March 30, 2015 at 10:03 PM UTC

Ohhhh okay. Thanks Rile! :)

Rainstruck March 30, 2015 at 10:03 PM UTC

Yw!

Milki March 30, 2015 at 10:03 PM UTC

/summon Milki
never learned calc

but from what i've read so far you don't get an answer because of an asymptote at x=0 but i'm probably wrong so don't listen to me

also jk summon me for precalc and below or competition math

JUBBINATOR March 31, 2015 at 10:03 PM UTC

bruh
u substitution
ez
so all you got is u = x^2+2x
so that means du = 2x+2
so what you got is (x+1) on top tho, so that's just du/2
so what you got now is 1/2 * integral from 0 to 1 of du/u
but you cant just use 0 becos that's gonna get you division by 0, so you gotta convert to improper integral
1/2 * lim(a->0) of integral from a to 1 of du/u
antiderive you get 1/2 * lim(a->0) of ln(u), and substituting u back in gives
1/2 * lim(a->0) of ln(x^2+2x) or 1/2 * lim(a->) of [ln(3) - ln(a)]
as a approaches 0 ln(a) approaches negative infinity so you got:
3- -infinity which is 3 + infinity = infinity; the 1/2 dont matter anymore
so it diverges 
c:
CCCCCCCCC:
ez

Glitchaye March 31, 2015 at 10:03 PM UTC

Answer is 10.

Ducksfanwaterloo March 31, 2015 at 10:03 PM UTC

how to math?

Jahaj March 31, 2015 at 10:03 PM UTC

It's actually 21.

weyheymarissa March 31, 2015 at 11:03 PM UTC

whats 9+10

Oraporo April 1, 2015 at 12:04 AM UTC

You lost me at math

JUBBINATOR April 1, 2015 at 1:04 AM UTC

Answer is 10.
STFU you ain't even showed your work you think you can just discredit my answer like that bruh you got another thing coming bruh i got a 96 in AP calculus BC on this test this ish is ez get on my level wait you cant cos i'll always be higher than you even if you had some dank ganja but ye 10 isn't the answer it's infinity like the scale reads when your nan steps on it.




jk ily but the answer is still infinity

BourbonBonobo April 1, 2015 at 2:04 AM UTC

Ok is this calculus?? I'm so confused.. I just started learning logs XD