integration (1 Viewer)

[shuning]

回复: Re: 回复: Re: integration

lol greaaaaaaaaat question shuning =P

but actually quite a few people in australia write it the way drongoski did xD
...even my bogan math teacher

for example today he gave us a math joke:

FIND:
integral(1/cabin)d(cabin) .... xDD

no no no... i mean actually drag stuff into the dx bits and work on it LOL


btw i dont get teh joke ...

 

[Drongoski]

Re: 回复: Re: integration

lol greaaaaaaaaat question shuning =P

but actually quite a few people in australia write it the way drongoski did xD
...even my bogan math teacher

for example today he gave us a math joke:

FIND:
integral(1/cabin)d(cabin) .... xDD

Exactly: = log cabin+ LinColn

GUSSSSSSSSSSSS

 

[shuning]

回复: Re: 回复: Re: integration


is it cuz i dont get it cuz i do std english? xD

 

[Drongoski]

sorry, you used u sub right??? i solved this question using u sub, and yeh i dont know what you did in the second line.

thanks

No. I did not. I avoid substituting as far as possible.

 

[shuning]

回复: Re: integration

btw Drongoski.... thank you very much man ^^ u have made me impress my cyber gf ( i think that's the only reason i post questions here 4 LOl )

 

[Trebla]

Re: 回复: Re: integration

that's how ppl in china writes it....

i hardly came across some aus high school students writes it that way... he prob learnd it in uni LOL

NOOB AUS HIGH SCHOOL EDUCATION XD

Heaps of high school students here do it that way. Many teachers (non-asian) teach that method as well.

 

[Timothy.Siu]

Re: 回复: Re: integration

Heaps of high school students here do it that way. Many teachers (non-asian) teach that method as well.

yeah i do it too, if it saves me a substituion

 

[eldore44]

Re: 回复: Re: integration


















at least thats how i got it.
do I then have to put it in terms of x?

 

[Timothy.Siu]

Re: 回复: Re: integration

at least thats how i got it.
do I then have to put it in terms of x?

thats a really really slow way.

if u want to use that substitution just do


u=sin^-1x
du=1/(root(1-x²) . dx

S u du=u^2/2
and sub it back in.

 

[youngminii]

Re: 回复: Re: integration

Can someone teach me that weird method? I've never seen it before ==;;

 

[GUSSSSSSSSSSSSS]

Re: 回复: Re: integration

lol all it is is writing the 1/sqrt(1 - x^2) as d(inverse(sinx)) **the derivative of sinx**


...?? u get?

 

[shuning]

回复: Re: 回复: Re: integration

Heaps of high school students here do it that way. Many teachers (non-asian) teach that method as well.

no1 in my school knows it.... ( even the 08ers... and last yr the whole 4u math 28 ppl got 90+ in 4u )

Can someone teach me that weird method? I've never seen it before ==;;

see this kid never saw it b4 too LOL

 

[GUSSSSSSSSSSSSS]

Re: 回复: Re: 回复: Re: integration

hmmmmmmmmm shuning you MASSIVE contradicting urself

you say heap of chinese know it

then u say no one in ur school know it

YOUR SCHOOL IS CHINESE !!!!!!!!!!!!!
(well at least the math classes are xD)

 

[youngminii]

Re: 回复: Re: 回复: Re: integration

==;; Wthell sif call me a kid.
And no I don't get it.

 

[shuning]

回复: Re: 回复: Re: 回复: Re: integration

hmmmmmmmmm shuning you MASSIVE contradicting urself

you say heap of chinese know it

then u say no one in ur school know it

YOUR SCHOOL IS CHINESE !!!!!!!!!!!!!
(well at least the math classes are xD)

calclus is not in the high school syllbus in china. they only start that in uni. that's y the chinese ppl in my school doesnt know it ^^

and that's y they do conics in yr 9 LOL ( nothing much left there to teach aye when there is no calclus xD )

 

[Dumbledore]

d/dx[arcsin(x)]=1/sqrt(1-x^2) => dx/sqrt(1-x^2) = d(arcsin(x));
thats how we were taught at least

and no i'm not posting during school

 

[Timothy.Siu]

its just changing what ur integrating with respect to.

e.g.

S sinxcosxdx=S sinx d(sinx)=sin²x/2

 

[cutemouse]

Re: 回复: Re: 回复: Re: integration

ibp

lol... You can try that... it wont get you very far.

 

[Dumbledore]

ibp can work
u= arcsin(x) v' = 1/sqrt(1-x^2)
u'=1/sqrt(1-x^2) v = arcsin(x)

S[arcsin(x)/(sqrt(1-x^2)]= arcsin^2(x) - S[arcsin(x)/(sqrt(1-x^2)]
2S[arcsin(x)/(sqrt(1-x^2)]= arcsin^2(x)
S[arcsin(x)/(sqrt(1-x^2)]= 1/2(arcsin^2(x))

but yea... it does suck

 

[shuning]

回复: Re: 回复: Re: 回复: Re: integration

lol... You can try that... it wont get you very far.

my cyber gf tried it..... she said u had to do it many times and u still get the answer.