MX1 exammm toomorrow:| (2 Viewers)

[zeebobDD]

hey guys do mind posting up some tough series sequence, integration(volume ,area n all that) questions need to test myself,

and i know this is could be in the mx1 marathon thread, but i dnt wanna flood it up with by asking ppl:L post questions which you think are tough

 

[Pfortune35]

resources section but if u want some good sequences and series and integration in the resources section theres a paper called vafa khafili do it

 

[Carrotsticks]

Define the series S(n):



a) Find a closed form for this series

b) Hence find

 

[Spiritual Being]

Shit shit shit, general maths topic test tomorrow! WTF is a ratio?! PlEaSe hElpp Mee x0x00x0x0 If bill earns $1 in 1 hour how much will he earn in 3 hours

 

[nightweaver066]

Ended up with 4.. unsure though..

 

[SpiralFlex]

Shit shit shit, general maths topic test tomorrow! WTF is a ratio?! PlEaSe hElpp Mee x0x00x0x0 If bill earns $1 in 1 hour how much will he earn in 3 hours

Roflcopters.

 

[Carrotsticks]

Ended up with 4.. unsure though..

Correct.

I love converging infinite series.

 

[nightweaver066]

My working out is pretty messy and there's probably a much quicker way lol.

Waiting on Spiral for a nice solution.

 

[Carrotsticks]

My working out is pretty messy and there's probably a much quicker way lol.

Waiting on Spiral for a nice solution.

Can you briefly outline your method?

Did you set up a triangular array of series?

 

[deswa1]

Can you briefly outline your method?

Did you set up a triangular array of series?

That's how I did it. Do you have any other questions similar to that one (I love those sorts of questions)?

 

[kingkong123]

Define the series S(n):



a) Find a closed form for this series

b) Hence find

Is the method for part (a) to turn it into sigma notation ie <a href="http://www.codecogs.com/eqnedit.php?latex=\sum_{n=1}^{n}n(\frac{1}{2})^{n-1}" target="_blank"><img src="http://latex.codecogs.com/gif.latex?\sum_{n=1}^{n}n(\frac{1}{2})^{n-1}" title="\sum_{n=1}^{n}n(\frac{1}{2})^{n-1}" /></a>

I tried that, then i split the sigma up into


And i tried to simplify both expressions into an AP x GP with their respective expressions, but i kept getting an expression that didn't satisfy the sum

Are you allowed to split up the sigma or am i doing an arithmetic error?

 

[zeebobDD]

Define the series S(n):


a) Find a closed form for this series

carrot what do u mean by closed form?:S

 

[zeebobDD]

oh my bad, sigma form

 

[Internet_Police]

Is the method for part (a) to turn it into sigma notation ie <a href="http://www.codecogs.com/eqnedit.php?latex=\sum_{n=1}^{n}n(\frac{1}{2})^{n-1}" target="_blank"><img src="http://latex.codecogs.com/gif.latex?\sum_{n=1}^{n}n(\frac{1}{2})^{n-1}" title="\sum_{n=1}^{n}n(\frac{1}{2})^{n-1}" /></a>

I tried that, then i split the sigma up into


And i tried to simplify both expressions into an AP x GP with their respective expressions, but i kept getting an expression that didn't satisfy the sum

Are you allowed to split up the sigma or am i doing an arithmetic error?

lol you can't do that.

That's like saying log(ab) = log(a) x log(b)

 

[Timske]

GL on ur exam got mine coming up soon :|

 

[nightweaver066]

Can you briefly outline your method?

Did you set up a triangular array of series?

Unsure what that means. I seperated it in to a GP, 1 + 1/2 + (1/2)^2 + ... And applied the sum of gp three times. I noticed a pattern and was able to deduce what the result would look like if I repeated this. Applied GP sum again, n-> infinity and I got my answer.

 

[Carrotsticks]

That's how I did it. Do you have any other questions similar to that one (I love those sorts of questions)?

Try to generalise the problem so instead of 1/2, it's 1/k. Generalisations and extensions are the best way to portray that you fully understand the concept.

Is the method for part (a) to turn it into sigma notation ie <a href="http://www.codecogs.com/eqnedit.php?latex=\sum_{n=1}^{n}n(\frac{1}{2})^{n-1}" target="_blank"><img src="http://latex.codecogs.com/gif.latex?\sum_{n=1}^{n}n(\frac{1}{2})^{n-1}" title="\sum_{n=1}^{n}n(\frac{1}{2})^{n-1}" /></a>

I tried that, then i split the sigma up into


And i tried to simplify both expressions into an AP x GP with their respective expressions, but i kept getting an expression that didn't satisfy the sum

Are you allowed to split up the sigma or am i doing an arithmetic error?

You can only take out constants, not terms of N.

Define the series S(n):


a) Find a closed form for this series

carrot what do u mean by closed form?:S

Closed form is a nice simple single expression (no summation or anything like that).

ie: The closed form for the series 1 + 1/2 + 1/2^2 + ... + 1/2^n would be acquired using the Sum of GP formula.

Unsure what that means. I seperated it in to a GP, 1 + 1/2 + (1/2)^2 + ... And applied the sum of gp three times. I noticed a pattern and was able to deduce what the result would look like if I repeated this. Applied GP sum again, n-> infinity and I got my answer.

That is the method I spoke of. Nice work.

 

[jnney]

hey guys do mind posting up some tough series sequence, integration(volume ,area n all that) questions need to test myself,

and i know this is could be in the mx1 marathon thread, but i dnt wanna flood it up with by asking ppl:L post questions which you think are tough

.__. do you go to HBHS? cus they have mx1 tomorrow too.

 

[Timske]

Homebush boys?!?!

 

[Bored_of_HSC]

gay school