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    WILL I BE GIVEN TRAPEZIUM RULE FORMULA AND other formulas like sum to infinity UN e.t.c.
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    (Original post by B_9710)
    First of all lets make all logs have the same base.
     \displaystyle \log_{100}[(2x+6)^2]=\frac{\log_{10}[(2x+6)^2]}{\log_{10}100}  =\frac{1}{2}\log_{10}[(2x+6)^2] then using the power rule you get  \log_{10}(2x+6) . As all logs in the equation have base 10 I'm not going to bother putting the base in any more.

     \displaystyle \log[(x-2)(x+2)]+\log[2(x+3)]=\log(x+2)+\log(x+3)
     \Rightarrow \log(x-2)+\log(x+2)+\log 2 +\log(x+3)=\log(x+2) + \log(x+3) . Notice 2 of the terms cancel on both sides of the equation.
    This leaves
     \displaystyle \log(x-2)+\log(2) = 0 \Rightarrow \log(2x-4)=0
    this obviously means that
     \displaystyle 2x-4=10^0=1 \Rightarrow \boxed{ x=5/2 }
    Thanks a lot. This has cleared up really well. The bases of the logs makes good sense now
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    (Original post by Hart)
    WILL I BE GIVEN TRAPEZIUM RULE FORMULA AND other formulas like sum to infinity UN e.t.c.
    Yes. But u may be confused by the trapezium rule formula in the book.

    Instead remember: h/2x(1st + last +2( + all the rest))
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    How much revision have you guys done?
    Done all the past papers and looked at some of the Solomon ones but always mess up in the questions with lots of marks.
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    Thanks my G. Do u think we'll get a log question that hard
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    (Original post by Namita Gurung)
    How much revision have you guys done?
    Done all the past papers and looked at some of the Solomon ones but always mess up in the questions with lots of marks.
    Thats exactly what i do! Its too late to do anyrhing now though
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    what paper is that question
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    (Original post by Hart)
    Thanks my G. Do u think we'll get a log question that hard
    Maybe not quite that hard but it will still be hard. These papers getting substantially more difficult over the past few years.

    A tip for logs. If U have a number sitting by itself amongst logs then u can convert that number into a log by making the base and the number after it the same.

    4 = 4log10 10
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    (Original post by Hart)
    what paper is that question
    He didn't take it from a paper. Look at th log questions from 2015 and 2014 and u will find some equally as hard
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    There's definitely gonna be a Hard trig and or a hard logs questions.
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    I just made up the question. I didn't realise it would work out so nicely so was a bit disappointed.
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    guys if I get a question like 3^2x-1 = 0.05, I can just use my calculator's log function to to work it out e.g. log 3 0.05 = 2x-1 right? Because on at least the 2010 c2 paper you had to use the 3rd law of logs to work it out...
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    I have never learnt change the bases log rule. If it comes up I'm going to drink bleach
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    (Original post by Heisenberg 23)
    I have never learnt change the bases log rule. If it comes up I'm going to drink bleach
    Don't remember it understand it. Take the general equation  a^b=c and take logs with different bases and just mess around and you will the result I posted earlier in the thread.
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    (Original post by Heisenberg 23)
    I have never learnt change the bases log rule. If it comes up I'm going to drink bleach
    It's just been explained to you thanks to someone. Rather than drinking bleach perhaps u should learn it in 5 mins
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    But we don't actually have to know it. I have never been taught it so surely I wouldn't need to know. Nor have I done any questions on it. My teacher wouldn't not teach me something that I need to know.
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    Pretty damn sure change of base isn't something you need to know for AQA, it's in the CGP book but I think they assume your calculator is crap which is the only reason you would use change base formula. Also on one of the 2010 core 2 papers, as I said in my last post there was a question that you can easily solve using a calculator log function but instead the mark scheme says you should use log laws. Maybe the specification changed or something? The current aqa spec says 'for exams from 2014' so maybe they changed it, and maybe it had the change base thing on the old spec?
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    http://www.thestudentroom.co.uk/show...35&postcount=2

    Name:  _IYGB 14.jpg
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    Thought that exam was quite nice. How did everyone else find it?
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    (Original post by greenmath)
    Thought that exam was quite nice. How did everyone else find it?
    It was solid😂 Low grade boundaries for certain.
 
 
 
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