BF2S Forums integration help

you're welcome.

...wow. i can't believe i overlooked that. thanks man.

1927 wrote:

Two questions.

1. How the fuck have you clever fuckers worked that out?

2. How do you think you will ever need to know that after school unless you become a scientist or something swotty?

1. its a bunch of rules and shit. its really easy.

2. its kind of necessary for me, seeing as i'm a civil engineering major.


edit: i feel like i should tell you that was only a chunk of the problem broken down after using partial fractions. the original looked like this:

integral (4x^3+3x^2-2x+1)/((x-1)^2*(x^2+2x+3))

Last edited by Ender2309 (2008-12-02 02:10:21)

Ender2309 wrote:

1927 wrote:

Two questions.

1. How the fuck have you clever fuckers worked that out?

2. How do you think you will ever need to know that after school unless you become a scientist or something swotty?

1. its a bunch of rules and shit. its really easy.

2. its kind of necessary for me, seeing as i'm a civil engineering major.


edit: i feel like i should tell you that was only a chunk of the problem broken down after using partial fractions. the original looked like this:

integral (4x^3+3x^2-2x+1)/((x-1)^2*(x^2+2x+3))

Wow, I'm glad my job seems easier than that, yes it has it's headaches but no way could I ever begin to try and untangle that bowl of spagetti math's that you did.

I can't speak French and neither can I speak math's.  Its a totally different level to myself, I still genuinely believe with the right people behind me I would be the best PM the Uk has ever had.

mcminty wrote:

Lol '27, as Ender said it's basically a bunch of rules and processes. You just look a the question, decide what needs to be done and the rest is pretty much the same each time (just with different numbers). And yeah, I'm a Civil Engineering major as well.

I'm a simple guy who cant stand complications (even though I tend to leave a wake of them where I go).  However, I cant begin to try and make that question simple, you make it sound simple by saying just follow the rules etc but even so.  I reckon you two sailed through school to the extent that you didn't need to revise and study as hard as the kids next to you, just one of the gifts you possess.

Could either of you give me an example of how in your job you have had to use or work out a formula/equasion (sp) as op had posted.

I'm a co director, we are a family business 96 years old.  Sign makers.  Our signs are made using software/computers/vinyl rather than with brushes, so English isn't as neccessary as it was 17 years ago when I left school.

The software does the maths for you.

I know the most important lesson/subject I learned in school was cooking as I cook every night.  I would like to say I.T or Computer Studies but I think you lot would laugh your arses off at me and ask 'What went wrong'?  I bet your gobsmacked when I tell you I passed my pc stuff with 'Distinction'.  Its probably just basic shit but even so.

I can't stay too serious for too long so I will finish this one post by saying my fav subject was Colouring in and Sand Pit time.  Joking aside I do actually use the colouring in bit when my colour printer goes tits up and I have proofs to submit.

White-Fusion wrote:

27' they proberly worked very hard in school, and once you understand the rules of algebra etc. I guess they just keep learning new rules and studying, and for them complicated rules etc are fine for them.

Bingo.

I wanted to be an Engineer. I knew I needed the maths. I worked my arse off. The stuff that Ender asked help for is easy to me now because it was part of my latest maths course at uni.


On the flipside, I'd have no idea how to do what you do..

mcminty wrote:

White-Fusion wrote:

27' they proberly worked very hard in school, and once you understand the rules of algebra etc. I guess they just keep learning new rules and studying, and for them complicated rules etc are fine for them.

Bingo.

I wanted to be an Engineer. I knew I needed the maths. I worked my arse off. The stuff that Ender asked help for is easy to me now because it was part of my latest maths course at uni.

You sound like my mates, though they are doing Chem Engineering and Electrical Engineering/Computer Science respectively......

mcminty wrote:

White-Fusion wrote:

27' they proberly worked very hard in school, and once you understand the rules of algebra etc. I guess they just keep learning new rules and studying, and for them complicated rules etc are fine for them.

Bingo.

I wanted to be an Engineer. I knew I needed the maths. I worked my arse off. The stuff that Ender asked help for is easy to me now because it was part of my latest maths course at uni.


On the flipside, I'd have no idea how to do what you do..

exactly. it looks hard but when you've put the work in to get to this point its fairly simple. yeah you run into occasional hitches but more or less every problem is exactly the same thing with different numbers. that's the beauty of math, you only have to learn it once.

Maths was the one part of my education that went really wrong. I was (and still am) amazingly good at doing mental maths in my head, I was extremely good with numbers, so I decided to take it as an A level (UK), but the level of work went up, and I had to deal with all these equations, rules etc. for some reason my brain couldn't get around it very well, the teacher was awful which didn't help, and I probably should have worked harder....Ended up just passing, 2 marks from a fail.

Good thing I was an ace at chemistry, biology and economics to save me ....but the fact is I don't use any of these subject in what I do now, so meh ..well economics I do, kinda.

Last edited by justice (2008-12-02 12:23:44)

JoshP wrote:

Sydney wrote:

Supposed to move f(x) = x^2+1 by the vector (-1 | 1), I know it's easy and I'll feel like a dumbass when I figure it out...

because i'm retarded and i've forgotten wether vectors are (x | y) or (y |x ) you might need to swap these round, but:

change x to x-1 and simplify it         (assuming the x bit of the vector is 1)
then take off 1 from the equation      (assuming the y bit of the vector is -1)

Yeah, I just found the rule

g(x)=f(x-a)+b

You did it opposite, but correctly.

mcminty wrote:

Lol '27, as Ender said it's basically a bunch of rules and processes. You just look a the question, decide what needs to be done and the rest is pretty much the same each time (just with different numbers). And yeah, I'm a Civil Engineering major as well.

you two could be me in 2 years. 

mcminty wrote:

I believe it is:

ln|x² + 2*x + 3| + 2*tan^-1(x+2) + C , where C is the constant of integration.

Shall check in Maple, and write the working out if ya want...



Edit: Fucked up the arctan part..

Apparently the overall thing should be:

ln|x² + 2*x + 3| + (√2)*tan^-1[(2*x+2)*(√2)/4] + C



But yeah, just separate the integral so in one part you get a logarithmic function, and an arctan function in the other part.

No way, I just had a test on taht today.

Last edited by aerodynamic (2008-12-02 14:40:31)