IA Type I -- Logarithm Bases

[koolchik]

hey i have the same portfolio but i dont get hoe to start.!!!plz do help.

[defyIB93]

I am having to write this portfolio. I have completed the first part, but I am unsure of how to start the next part.

"Now calculate the following, giving your answers in the form p/q..."

the logs are:

log (base 4) 64,log (base 8) 64, log (base 32) 64

log (base 7) 49, log (base 49) 49, log (base 343) 49

log (base 1/5) 125, log (base 1/125) 125, log (base 1/625) 125

log (base 8) 512, log (base 2) 512, log (base 16) 512

Then, it asks to describe how obtain the third answer in each row from the first two answers. And then create two more examples that fit the pattern above.

HELP!!!

[Peachez]

You will find it here:

[Just Do It*]

You guys, I have my IA due in 3 days, and I've done most of it.

I just need some help on how to calculate the following giving an answer in the form of p/q

log (base 4) 64,log (base 8) 64, log (base 32) 64

log (base 7) 49, log (base 49) 49, log (base 343) 49

log (base 1/5) 125, log (base 1/125) 125, log (base 1/625) 125

log (base 8) 512, log (base 2) 512, log (base 16) 512

like i found the patter, but how to do it in that form?

also how do you actually start the introduction?

[Guest Artus]

1) In Math SL type 1, I chose "Logarithm Bases"...and I'm not sure if I'm understanding the question correctly...For the first pattern it says..."Write your expression in the form p/q where p nd q are integers."

The formula I found was a(n-1)/n...where n is the nth term...the question says that the numerator and the denominator need to be integers...Mine is not an integer...but when you substitue numbers for "n"...they will be integers eventually...also...it says that the formula needs to be a sequence...is mine considered a sequence...I was googling this to see if my answer was correct...but I found out that other people came up with another equation...k/n...(where k is the exponent of 8 and n is the exponent of the base)...I think that k/n makes more sence than my formula...even though my formula also works for all the terms in the formula...I'm not sure if that's what they are asking for...so my question is: Is my formula correct? Should I change the formula and write k/n? Or should I write both the formula I found (even though I think they won't want it) and the formula I found online?

2) Math type 2: I chose the "Fishing Rods" one...at the end it tells us to state the limitations of the quadratic equation...what does it mean by "limitations"?

Thanks in advance to anyone who is willing to help...

[Austin Glau]

1) When I did this portfolio, I found that

when log[m^n,m^k], and n is an integer,

log[m^n,m^k]=k/n

where n,m!=0

I guess you could use a(n-1)/n if the portfolio works that way, you shouldn't base your portfolio off of what others say. I wish the math teacher could help on these lol I was stuck for like 1 week and my math teacher just stood there, laughing i think

2)

Limitations of the quadratic equation would include interference outside of the closed system of the fishing rod like wind, stability, bounciness, ect.

[ibcrazy]

I just got the Logarithm Bases Portfolio yesterday and I've been trying to figure out the first pattern:

"Find and expression for the nth term of each sequence. Write you expressions in the form p/q, where p,q are integers. Justify your answers with technology."

I feel so dumb, but I have no idea how to even start!

Are they asking for a solution for n?

Or should n be in the expression?

Gah, please help...

[Guest Artus]

I just got the Logarithm Bases Portfolio yesterday and I've been trying to figure out the first pattern:

"Find and expression for the nth term of each sequence. Write you expressions in the form p/q, where p,q are integers. Justify your answers with technology."

I feel so dumb, but I have no idea how to even start!

Are they asking for a solution for n?

Or should n be in the expression?

Gah, please help...

1) They want you to come up with a formula that has "n" in it...you should be able to use your formula to find any term in the sequence...for instance...if you want to find the first term...just substitute 1 for "n" and solve...that should give you the value of the first term...if you want to find the 3rd term...substitute 3 for n and solve...that's how it should be...and yes n should be in the expression...

You can check the link "Peachez" posted...

[Eternalx]

Hello, just a quick question. With the graphs, I think you plot sequence equation and the y-intercept?

But How do I do this on the calc or graphical analysis? Thanks ^^

Edited March 1, 2010 by Eternalx

[supernova4]

I hope this doesn't sound dumb, but I solved all of the SL math problems except for the last. Let find the general statement that expresses logabx in terms of c and d. I need help desperately! If anyone knows and is willing to share I'd welcome advice with open arms.

[deissi]

You should be able to derive it mathematically yourself. If you can't, try to find the pattern between the answers in the previous question.

[M6T6R6]

I am currently working out the logarithm bases assesment for IB, and I have understood and completed everything up until:

Test the validity of your general statement using other values of a, b, and x.

I know this shouldn't be difficult but to accurately encompass a, b, and x, I believe I would have to test about 36 combinations and I don't think that's what they're looking for.

Could you give me direction as to what I should do?

Help very much appreciated - this is my first IB 'assessment' .

[Daedalus]

I am currently working out the logarithm bases assesment for IB, and I have understood and completed everything up until:

Test the validity of your general statement using other values of a, b, and x.

I know this shouldn't be difficult but to accurately encompass a, b, and x, I believe I would have to test about 36 combinations and I don't think that's what they're looking for.

Could you give me direction as to what I should do?

Help very much appreciated - this is my first IB 'assessment' .

Here you can use excel or TI 84 (table - independent variable - ask) but basically as far as I understand you have to find out if a, b and x can be negative or zero. Also can they be irregular numbers or only integers? Sometimes just by definition they can't, and you have to find out what the limitations are and then explain them using theory (i.e. a certain constant cannot be zero because you can't divide by zero, or another one can't be negative because you can't find the root of that, etc.)

[Mahuta ♥]

Like said above, you have to eliminate negative values or zero, by mathematical logic. Once you have done that, state it clearly before you start the validation to make it clear that you understand this concept, the more you state and clarify things the better your IA is.

Before trying out differnt values, make general formulae, for example:

Log(-ve)+ve --->possible or not

Log (+ve)-ve ---->possible or not

...etc

Decide what kind of numbers you're going to use: integers..irrational..etc

When I did this project, I had 27 validations, it may seem a lot, but that was my method, and I got what I wanted.

Make sure you dont leave anything that could lose you marks. A bit longer than usual is much much better than too short.

Goodluck

[M6T6R6]

Thanks for attempting to help guys! Mahuta do you think you could explain:

Log(-ve)+ve --->possible or not

Log (+ve)-ve ---->possible or not

...etc

I am not sure our teacher has taught us enough to do this portfolio - we only did logs for about 3 days.

I was planning to test: 0, integers, rational, irrational, etc. You would plug these into your general statement in terms of c and d (correct me if I am wrong).

If that's the case it'll be a lot simpler.

By the way: Mahuta, is IB in India better? I heard that they get the highest IB test results of all nations, is this true?

Edited June 4, 2010 by M6T6R6

[Mahuta ♥]

First off, how would I know anything about India? I am not Indian and I have never been there, lol.

Secondly,

Log(-ve)+ve --->possible or not

Log (+ve)-ve ---->possible or not

the term in brackets is just the base- as shown below.

So basically, before you start off, you have to make it clear that you know rules and basis of logs.

For example:

You can only have: log(-ve)+ve if the answer is even; since when multiplying a negative by an even power, gives you a positive. This may sound all complicated to you but just put a general formula in front you: log(a)b , then just decide in what situations can 'a', for example be negative and give you a integer and not a 'math error' on you GDC. Similarly decide, in what situations can 'b' be a negative.

Then try can you have a postive 'a' and negative 'b'...etc. Just try simply values and start by integers first when making these clarification, BEFORE you start the validation.

And yes, you can use the integer, rational and irrational.

[M6T6R6]

First off, how would I know anything about India? I am not Indian and I have never been there, lol.

Secondly,

Log(-ve)+ve --->possible or not

Log (+ve)-ve ---->possible or not

the term in brackets is just the base- as shown below.

So basically, before you start off, you have to make it clear that you know rules and basis of logs.

For example:

You can only have: log(-ve)+ve if the answer is even; since when multiplying a negative by an even power, gives you a positive. This may sound all complicated to you but just put a general formula in front you: log(a)b , then just decide in what situations can 'a', for example be negative and give you a integer and not a 'math error' on you GDC. Similarly decide, in what situations can 'b' be a negative.

Then try can you have a postive 'a' and negative 'b'...etc. Just try simply values and start by integers first when making these clarification, BEFORE you start the validation.

And yes, you can use the integer, rational and irrational.

\thanks, I get it now! BY the way, sorry about that last post. I brashly glanced at your nationality and mistook it for India, even though these flags look nothing alike. Better brush up on geography!

[M6T6R6]

First off, how would I know anything about India? I am not Indian and I have never been there, lol.

Secondly,

Log(-ve)+ve --->possible or not

Log (+ve)-ve ---->possible or not

the term in brackets is just the base- as shown below.

So basically, before you start off, you have to make it clear that you know rules and basis of logs.

For example:

You can only have: log(-ve)+ve if the answer is even; since when multiplying a negative by an even power, gives you a positive. This may sound all complicated to you but just put a general formula in front you: log(a)b , then just decide in what situations can 'a', for example be negative and give you a integer and not a 'math error' on you GDC. Similarly decide, in what situations can 'b' be a negative.

Then try can you have a postive 'a' and negative 'b'...etc. Just try simply values and start by integers first when making these clarification, BEFORE you start the validation.

And yes, you can use the integer, rational and irrational.

\thanks, I get it now! BY the way, sorry about that last post. I brashly glanced at your nationality and mistook it for India, even though these flags look nothing alike. Better brush up on geography!

1 brief question - LAST ONE. I won't bug you anymore. When I am testing the validity, do I plug in a,b, and x into the process I used to find the general statement.

E.g. log(a)x=c log(b)x=d

log(-2)4=c log(-4)4=d

-2^c=4 -4^d=4

[Mahuta ♥]

Yes, I plugged in a, b and x.

And don't worry, we're here to help.

[jsoccerdog]

So I don't understand the last part of a type 1 Math SL IA. It says:

Let logaX=c and logbX=d. Find the general statement that expresses logabX, in terms of c and d (a and b in the logs are both supposed to be subscript).

Any help would be greatly appreciated!