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# base change

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1. hi how do you change the base of this please to make same
logbase3 (2-3x) = logbase9 (2-3x)

how can u make the logbase 9 same as logbase 3?what formula thanks
2. The formula is loga(x) = logb(x)/logb(a)
3. (Original post by otrivine)
hi how do you change the base of this please to make same
logbase3 (2-3x) = logbase9 (2-3x)

how can u make the logbase 9 same as logbase 3?what formula thanks

We want to convert it into base

4. (Original post by otrivine)
hi how do you change the base of this please to make same
logbase3 (2-3x) = logbase9 (2-3x)

how can u make the logbase 9 same as logbase 3?what formula thanks
Use this
Attached Thumbnails

5. (Original post by otrivine)
hi how do you change the base of this please to make same
logbase3 (2-3x) = logbase9 (2-3x)

how can u make the logbase 9 same as logbase 3?what formula thanks
In this case 2-3x =1 this is so because the log terms must both be zero and the log of one is zero.

So x equals 1/3 The base 3 and base 9 are irrelevant.
6. got it guys thank you
7. (Original post by steve2005)
In this case 2-3x =1 this is so because the log terms must both be zero and the log of one is zero.

So x equals 1/3 The base 3 and base 9 are irrelevant.
and for binomial expanssion if for example (3-2x) power n
how do we work out n/?
8. (Original post by otrivine)
and for binomial expanssion if for example (3-2x) power n
how do we work out n/?
What does n/ mean?

(3-2x)^n what is the question?
9. (Original post by steve2005)
What does n/ mean?

(3-2x)^n what is the question?
like you are given with (3-2x) power n and they ask you to find n how do you do that?
10. (Original post by otrivine)
like you are given with (3-2x) power n and they ask you to find n how do you do that?
So you are given (3-2x)^7 and asked for the value of n. I would say the answer was seven.

Give us a REAL question and perhaps we can help.
11. (1+x/2)power n , where n is a postivie integer is 7 .
find the value of n
12. (Original post by otrivine)
like you are given with (3-2x) power n and they ask you to find n how do you do that?

With this much information it is impossible to find the value of 'n'.

The questions usually give some information about the coefficient of terms which allow to calculate it.
13. (Original post by otrivine)
(1+x/2)power n , where n is a postivie integer is 7 .
find the value of n
Did you invent this question?

Steve asked you to give a REAL question, you won't see such type of questions anywhere.
14. (Original post by otrivine)
(1+x/2)power n , where n is a postivie integer is 7 .
find the value of n
I may be missing something BUT I can't see a question. I suggest you give a real question.
15. (Original post by raheem94)
Did you invent this question?
no mate its in the book page 77 mixed excersise 5E question 6)a)
16. (Original post by otrivine)
no mate its in the book page 77 mixed excersise 5E question 6)a)
I suggest you compare what you have written to what is printed in the book.
17. (Original post by steve2005)
I suggest you compare what you have written to what is printed in the book.
oh sorry but how do u do it please tell me sir
18. (Original post by otrivine)
no mate its in the book page 77 mixed excersise 5E question 6)a)
If you don't like to take your time writing you full question then i think we shouldn't waste our time on you.

Yesterday you said that a question is in the C2 jan 2012 paper, without telling the board.
Several times you have posted questions regarding the book, without telling which module you are talking about.

And right now the question you wrote wasn't complete.

Here is the question:

Don't mind, but i have tried to explain you several times to tell us the full question, if you talk about a book then tell the module, which book is it, and if exam paper remember to tell the board.
19. (Original post by otrivine)
oh sorry but how do u do it please tell me sir
For doing the question, just expand

Equate the coefficient of in the expansion with 7.
20. (Original post by otrivine)
oh sorry but how do u do it please tell me sir

The question you posted is incomplete, please give the full question as printed in the book.

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