Volume (2 Viewers)

[crammy90]

when do you know when to split up an integral under a curver and then find the volumes of these two integrals and add them, rather than just taking the whole integral?

and those exact ratio's. are they in radians or degrees lol
maths is hard

 

[tommykins]

please specify questions, i'm confused as to what you're asking.

exact ratios of what?

 

[mick135]

when do you know when to split up an integral under a curver and then find the volumes of these two integrals and add them, rather than just taking the whole integral?

and those exact ratio's. are they in radians or degrees lol
maths is hard

always assume radians dude,
its like a negative times a negative is a positive, its just a basic rule.
try to graph or imagine what the function looks like, and see whether some of the area you finding (before you multiply by pi) is in the negative section. if so, then add it.
if not - just do it normally and you should be good
you also might/probably need to split up the area under a curve when your finding the area between 2 curves.

wait for tommykins to respond to this thread - he's the best at maths i've seen on this website haha

 

[Graceofgod]

when do you know when to split up an integral under a curver and then find the volumes of these two integrals and add them, rather than just taking the whole integral?

and those exact ratio's. are they in radians or degrees lol
maths is hard

Now. You do the whole integral when you are finding the difference between two curves. You split it up when they cross over.

You also split it up when you are finding the area between one curve and an axis.
You must do separate integrals above and below the axis, and make sure you absolute value that below the axis.

Exact ratios can be either in radians or degrees. I think what you are referring to is in degrees though, but yeah, you need to go back to how they are derived I think.

You really need to go back and study a lot of maths!... And ask better questions next time! <3

 

[tommykins]

always assume radians dude,
its like a negative times a negative is a positive, its just a basic rule.
try to graph or imagine what the function looks like, and see whether some of the area you finding (before you multiply by pi) is in the negative section. if so, then add it.
if not - just do it normally and you should be good
you also might/probably need to split up the area under a curve when your finding the area between 2 curves.

wait for tommykins to respond to this thread - he's the best at maths i've seen on this website haha

hahahaha no fricking way, that title goes to lolokay.

 

[crammy90]

hah he responded before ya
i meant those exact ratio triangles like tan45 = 1 and stuff. like cos 60 = root3/2

and a specific question would be this trial i did but there was one in 2005 6 c ii
it tells you to split it. I got that once cause it told me. In the trial it didnt tell me but they did it
thanks for the quik responses
and how do u guys get so good lol
do u just keep doing past papers?
an asain guy floggin 4unit said he does past papers and the questions he gets wrong he looks up that topic in the book and does exercises?
is that the best way?

 

[Graceofgod]

Read what I said... -_- I know what you meant..

The exact ratios are based on triangles. But yes, the ones you are referring to are in degrees..

 

[crammy90]

Read what I said... -_- I know what you meant..

The exact ratios are based on triangles. But yes, the ones you are referring to are in degrees..

sorry i missed your post before. i didnt realise 2 people posted at once
thanks

 

[mick135]

please specify questions, i'm confused as to what you're asking.

exact ratios of what?

exact ratios normally mean crap like sin(pi/6) = 1/2, cos(pi/3) = 1/2, tan(pi/4) = 1 and so on.
lol tommy, you can answer any question the BOS throws at you - but you can't explain in general terms haha (i'm just laughing cause i can kinda explain something that you can't when i know your way better than me at this subject haha)

 

[tommykins]

exact ratios normally mean crap like sin(pi/6) = 1/2, cos(pi/3) = 1/2, tan(pi/4) = 1 and so on.
lol tommy, you can answer any question the BOS throws at you - but you can't explain in general terms haha (i'm just laughing cause i can kinda explain something that you can't when i know your way better than me at this subject haha)

nah i know about exact ratios, but his question was kind of confusing.

exact ratios in radians or degrees ? well, sin pi/6 = sin 30 anyways, and if they do give you exact ratios there will be a pi in it, they wouldn't give you a decimal.

 

[lyounamu]

hahahaha no fricking way, that title goes to lolokay.

That's only among 09'ers.

 

[bubblesss]

what with maths geniuses all over the place i feel so dumb!!!!!!!!!

eg: tommykins,lolokay,lyounamu etc etc

 

[crammy90]

what with maths geniuses all over the place i feel so dumb!!!!!!!!!

here here

 

[tommykins]

回复: Re: Volume

That's only among 09'ers.

lol out of the '08ers i'd say mark576 although he doesn't post much.

 

[lyounamu]

Re: 回复: Re: Volume

lol out of the '08ers i'd say mark576 although he doesn't post much.

I thought pwnage, midfile were up there too. If giles gardam comes here often, he would be the best though, lol. (he actually came here for few times last year)

 

[tommykins]

回复: Re: 回复: Re: Volume

I thought pwnage, midfile were up there too. If giles gardam comes here often, he would be the best though, lol. (he actually came here for few times last year)

yeah midi is up there with her ranks and marks but i don't see her answering many questions (not saying that she CAN'T answer them).

meh doesn't matter lols