C2 Logs Question - Calling Insparato!!!! Watch

vector
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#1
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#1
Hi everyone,

I have a logs question that I'm having problems with. I saw the job insparato did on the other one, and wondered if it could be repeated ???

It was explained in school, but I forgot how it was done. This is for WJEC C2.

I can do part (a) Ok, and I remember that the rule in part (a) had to be used for part (b), I just can't remember how

Thanks in anticipation for your help,
Michael
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insparato
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Hi vector

Okay the integral of log10 x = 0.5628

the integral of log1010x

= integral of log1010 + integral of log10x ---- as log xy = log x + log y same applies if its an integral in front of it.

= 0.5628 + integral of 1 in the limits 3 and 1 --- the integral of 1 is found by the fact that log1010 = 1

intergal of 1 = x therefore [x] limits 3 to 1 = [3]-[1] = 2

so the integral of log1010x = 2+ 0.5628 = 2.5628
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*LEGEND*
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Im gonna go for it! but this might be wrong!

Log10 (10x) = log10 10 + log10 x
since log10 10 = 1, then that means it is simplified to...
1 + log10 x
So the answer is 1.5628?
i think the integration thing is to confuse you..
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bigbadb1319
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btw, guyz, how do u prove part a?
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*LEGEND*
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oh wait insparato is right, you have to integrate the 1
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AlphaNumeric
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(Original post by bigbadb1319)
btw, guyz, how do u prove part a?
Write x = a^{\log_{a}x} etc and use the rules of indices.
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vector
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Thanks for that - give me 5 mins to get my head round it!

to prove part a:

log(a)xy = log(a)x = log(a)y

x=a^p y=a^q

p=log(a)x q=log(a)y

xy = a^p * a^q = a^(p+q)
(p+q)=log(a)xy

Remember p=log(a)x q=log(a)y

log(a)x + log(a)y = log(a)xy

Michael
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vector
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Insparato you are a genius!!! Are you in yr 13 / uni or what?

Hope they aren't that mean tomorrow!!!!

Good luck all!

Michael
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insparato
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Nope im in year 12, still 16 .

Thanks i hope they arent mean either.
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Desi
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i've never come across part a of that question in the edexcel past papers :confused:
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Dabster
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because thats a WJEC C2 question
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vector
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Not in edexcel because I'm doing WJEC.

You have impressive mathematical ability Insparato! What board was that other log question you answered from (the translation of the graph). I've never seen anything like that before.

I'm also still 16 - did my GCSE's a year early.

Michael
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Dabster
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so what core Edexcel module is the WJEC C2 equivilant to? im guessing c3
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insparato
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Ive done so many logs today can you show me the thread i did it on lol.

I didnt do my gcse a year early i did mine in year 11. I got an A 515/600 overall. I just kinda sprouted in a level. But i am no genius there are much better people than i am. I know 2 mathematicians in my school that are definately better than me. So you know theres always someone better than you .
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vector
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That's life!

I'm not sure on points, but I got 7A*s and 4As at GCSE, plus a C I got in year 8.

I managed full marks in the January C1 module, needless to say I only have C2 to worry about tomorrow :cool:

michael
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insparato
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I didnt do as well as i should've in C1 still got an A though. Im hoping i can do better in C2 tomorrow.
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vector
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What board are you doing?
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insparato
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Edexcel.
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