Calculus Question....

[Reincarnate]

Re: Calculus Question....

also emerald get your butt back into PE

[nois-or-e]

Re: Calculus Question....

//moved to 'Homework & General Info' sub forum

[25thhour]

Re: Calculus Question....

//moved to 'Homework & General Info' sub forum

I can never seem to find this darn thread... I knew it was there. Lol.

[emerald000]

Re: Calculus Question....

emerald:
you go from
h = (15 - πr³) / (3πr²) up top which is right
to h = 15 / (4πr²) on the bottom which isn't
prolly why we have differing h values

If I plug my radius into your top equation I get 1.37 etc

Corrected. Forgot to update that equation after my correction.

also emerald get your butt back into PE

Finished school today, so I'll have a lot of free time in the next weeks to do PE and FFR coding.

[25thhour]

Re: Calculus Question....

Well ****. I am totally effing lost with to what just happened. I am terrible with algebra so I don't know what happened when simplifying after the "h" was replaced...

[emerald000]

Re: Calculus Question....

It helps if you write it down on a sheet of paper. It is pretty hard to visualise when it is in text like that.

2πrh + πr² + sqrt(2)πr² =

Replace h = (15 - πr³) / (3πr²)

2πr((15 - πr³) / (3πr²)) + πr² + sqrt(2)πr² =

Simplify the πr in the first term.

2((15 - πr³) / (3r)) + πr² + sqrt(2)πr² =

Distribute the 2:

(30 - 2πr³) / (3r) + πr² + sqrt(2)πr² =

Here, I actually skipped a few steps.
Separate the first term into 2.

30 / (3r) - 2πr³ / (3r) + πr² + sqrt(2)πr² =

Simplify the first term:

10 / r - 2πr³ / (3r) + πr² + sqrt(2)πr² =

Simplify the second term:

10 / r - 2πr² / 3 + πr² + sqrt(2)πr² =

Add the second and third term:

10 / r + πr² / 3 + sqrt(2)πr² =

Reorder the terms for my OCD:

sqrt(2)πr² + πr²/3 + 10/r

PS: We should totally have LaTeX. That would make things so much prettier.

[25thhour]

Re: Calculus Question....

In the last step you are adding 1 pi to sqrt(2)piR^2, why doesnt it change?

[iironiic]

Re: Calculus Question....

PS: We should totally have LaTeX. That would make things so much prettier.

I second this. In some forums, you can put [itex][/itex] tags and that will convert the coding to nicer looking formulas. Not sure how one would implement this though.

As for the question, seems like a bunch of people gave you enough help. I'm also too tired to think right now haha.

[emerald000]

Re: Calculus Question....

In the last step you are adding 1 pi to sqrt(2)piR^2, why doesnt it change?

Not sure where you are talking about. Is it the: 3sqrt(2)π + π? It could be factored to (3sqrt(2)+1)π, but this is hardly prettier than the other form.

I second this. In some forums, you can put [itex][/itex] tags and that will convert the coding to nicer looking formulas. Not sure how one would implement this though.

I'll see what could be done about it.

[25thhour]

Re: Calculus Question....

Nevermind man, I durped again and figured out what happened. Gah, I'm out of it tonight. I need to get drunk.

[hi19hi19]

Re: Calculus Question....

I second this. In some forums, you can put [itex][/itex] tags and that will convert the coding to nicer looking formulas. Not sure how one would implement this though.

http://www.phpbb.com/community/viewtopic.php?t=653165

[25thhour]

Re: Calculus Question....

I will send out credits after I get back from my rugby game Thank you veeeery much

[prefx]

Re: Calculus Question....

Lolwhat did he banned for the alcohol reference?

[Reincarnate]

Re: Calculus Question....

lol wtf?