Results are out! Find what you need...fast. Get quick advice or join the chat
Hey there Sign in to join this conversationNew here? Join for free

Differentiation C3

Announcements Posted on
    • Thread Starter
    • 16 followers
    Offline

    ReputationRep:
    Am stuck on this..how to differentiate : log_2 (3x/x-1)

    If I could convert it to ln I should be able to do it but dunno how to convert it to ln


    +rep
    • 10 followers
    Offline

    ReputationRep:
    Do you know the change of base formula? Written in terms of ln it is:

    \log_a b = \dfrac{\ln b}{\ln a}
    • 70 followers
    Offline

    ReputationRep:
    (Original post by notnek)
    Do you know the change of base formula? Written in terms of ln it is:

    \log_a b = \dfrac{\ln b}{\ln a}
    So ln(6x/x-1)? How do you differentiate that?
    • 10 followers
    Offline

    ReputationRep:
    (Original post by Junaid96)
    So ln(6x/x-1)? How do you differentiate that?
    Use the log law:

    log \dfrac{A}{B} = \log A - \log B

    Or differentiate it directly using the normal method for finding the derivative of a natural logarithm. You need to use the quotient rule for that.
    • Thread Starter
    • 16 followers
    Offline

    ReputationRep:
    (Original post by notnek)
    Do you know the change of base formula? Written in terms of ln it is:

    \log_a b = \dfrac{\ln b}{\ln a}
    \log_a b = \dfrac{\ln b}{\ln a}

    oh that's it ..I had forgotten that
    • 10 followers
    Offline

    ReputationRep:
    (Original post by arvin_infinity)
    \log_a b = \dfrac{\ln b}{\ln a}

    oh that's it ..I had forgotten that
    The general law works for any base:

    \log_a b = \dfrac{\log_c b}{\log_c a}

    If c is the number e then you have the law which I gave in my last post.
    • Thread Starter
    • 16 followers
    Offline

    ReputationRep:
    (Original post by notnek)
    The general law works for any base:

    \log_a b = \dfrac{\log_c b}{\log_c a}

    If c is the number e then you have the law which I gave in my last post.
    You are a legend
    This goes straight to my notes..
    • 70 followers
    Offline

    ReputationRep:
    (Original post by arvin_infinity)
    You are a legend
    This goes straight to my notes..
    I don't mean to sound patronising, but why you have notes? I've never made notes for maths
    I always just did examples on paper and binned them afterwards - all the notes I need are neatly typed up in the textbook. It's pretty much the same for most people in my set, except most of them keep their example questions.
    • Thread Starter
    • 16 followers
    Offline

    ReputationRep:
    (Original post by Junaid96)
    I don't mean to sound patronising, but why you have notes? I've never made notes for maths
    I always just did examples on paper and binned them afterwards - all the notes I need are neatly typed up in the textbook. It's pretty much the same for most people in my set, except most of them keep their example questions.

    Yh that was last year when I got an A for math..this year need A*..it's v different
    • 70 followers
    Offline

    ReputationRep:
    (Original post by arvin_infinity)
    Yh that was last year when I got an A for math..this year need A*..it's v different
    I also need an A*, but I don't find notes very useful at all, as maths is not something you can rote learn - you learn it by doing it. Practice is key

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide to join now Processing…

Updated: June 10, 2012
New on TSR

So how did you do?

Come into the GCSE forum to share your grades

Article updates
Reputation gems:
You get these gems as you gain rep from other members for making good contributions and giving helpful advice.