help! (1 Viewer)

[poisongirl]

help!
im not doing very well with these topic
TRAPEZOIDAL RULE and VOLUMES OF SOLIDS OF REVOLUTION and VOLUMES FORMED BETWEEN 2 CURVES AROUND AN AXIS

any1 know of a site to get help on these? or do i need a tutor?

 

[velox]

Post your questions on here and learn.

 

[tennille]

Have you tried asking your teacher? I know it's sometimes a pain, but they're there to help. I dont think you'd need a tutor. Check websites (I dont know any, sorry- maybe look on Google), ask people (including BOS people) and everything, before getting a tutor.

 

[FinalFantasy]

just read a text book a few more times, integration is easy to understand i think

 

[Trev]

Just do what Tenille and FinalFantasy said, go through the textbook and try and understand the process of it, try not to do "rote" learning. If you still have trouble, ask your teacher.

 

[DistantCube]

You just need to know the formulae and know how to apply them and you should be fine.

These are slightly different from the book, but its the same, and I think it looks nicer.

Trapezoidal rule:
(h/2)[f(a)+f(b)-2(f(x1)+f(x2)+...+f(xn))] ; where h is the width of one "strip", a is the first function value, b is the last function value, and x1 etc are the function values in between. You must evaluate the function for each of the values.

Simpsons rule:
(h/3)[f(a)+f(b)+2(f(odds))+4(f(evens))] ; where h, a and b are the same as above. The "odds" are all the odd numbered values in between and the "evens" are the even numbered values in between, again evaluating the function with the values.

Volume:
pi x the integral from a to b of the function squared. The only thing with this is which axis you're revolving around, if its the x axis, then y must be the subject of the equation and if its the y axis then you must rearrange the equation so x is the subject.

Area between two curves:
The integral from a to b of the top curve minus the bottom curve.

 

[poisongirl]

THANKS GUYS!!
i'll do wat u all said

 

[Tarni1]

hey!
this may help:
These are other formulas for trapazoidal and simpsons rule our teacher uses - much easier!!
TRAPAZOIDAL= w/2 x (first y + last y + (2 x other y's) )
(w=difference bewteen each y)
(NB: w/2 = w divided by 2, w over 2 in other words)
SIMPSONS = w/3 x (first y + last y + (4 x middle y)

hope it helps !

 

[acmilan]

hey!
this may help:
These are other formulas for trapazoidal and simpsons rule our teacher uses - much easier!!
TRAPAZOIDAL= w/2 x (first y + last y + (2 x other y's) )
(w=difference bewteen each y)
(NB: w/2 = w divided by 2, w over 2 in other words)
SIMPSONS = w/3 x (first y + last y + (4 x middle y)

hope it helps !

Er would that simpsons one work? multiplying everything in the middle by 4?

 

[velox]

isn't it 4,2,4,2 etc?

 

[acmilan]

As far as i know.

 

[DistantCube]

I'm pretty sure it is 4,2,4,2...which is what I wrote before...

 

[gibbo67]

I'm pretty sure it is 4,2,4,2...which is what I wrote before...

yeah, you're right