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    How do u differentiate (3x^2 + 2x)/(6x+4)
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    Quotient rule?
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    (Original post by apaul322)
    How do u differentiate (3x^2 + 2x)/(6x+4)
    \displaystyle \frac{3x^2+2x}{6x+4} = \frac{x(3x+2)}{2(3x+2)} = \frac{x}{2}
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    (Original post by RDKGames)
    \displaystyle \frac{3x^2+2x}{6x+4} = \frac{x(3x+2)}{2(3x+2)} = \frac{x}{2}
    Note: You still need to differentiate by quotient rule.
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    (Original post by Lord Nutter)
    Note: You still need to differentiate by quotient rule.
    No you don't...
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    (Original post by Lord Nutter)
    Yes you do as the answer is 0.5.

    All you did was simplify you forgot to differentiate
    \dfrac{x}{2} = \dfrac{1}{2}x

    You don't need to use the quotient rule to differentiate ax.
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    (Original post by Notnek)
    \dfrac{x}{2} = \dfrac{1}{2}x

    You don't need to use the quotient rule to differentiate ax.
    Okay I see how you have got the x/2 but how is this differentiated?
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    (Original post by Lord Nutter)
    Okay I see how you have got the x/2 but how is this differentiated?
    As I said above, you just have a constant multiplied by x e.g. the derivative of 2x is 2 and the derivative of -10x is -10. It's the same principle here but with (1/2)x.
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    (Original post by Lord Nutter)
    Yes you do as the answer is 0.5.

    All you did was simplify you forgot to differentiate
    ...

    I wasn't even going for differentiation. I simplified the expression for OP so that they wouldn't need to even use the quotient rule as it's obsolete here.
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    (Original post by Lord Nutter)
    Yes you do as the answer is 0.5.

    All you did was simplify you forgot to differentiate
    nope
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    (Original post by RedGiant)
    nope
    what?
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    (Original post by tome123)
    what?
    I meant the answer is 0.5 you just don't need the quotient rule.
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    (Original post by RedGiant)
    no need for quotient rule
    alright alright I see now. I thought people were saying that you leave it as x/2 and I was like wtf no

    Brain won't function properly at 12 at night
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    (Original post by Lord Nutter)
    Oh oh ah I see now.

    Brain won't function properly at 12 at night
    Mine's the opposite, I like doing maths at night :3
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    (Original post by RDKGames)
    ...

    I wasn't even going for differentiation. I simplified the expression for OP so that they wouldn't need to even use the quotient rule as it's obsolete here.
    You didn't answer the full question though.

    The OP asked how to differentiate it and you left it at the simplified version - assuming that the OP knew what to do. Sure quotient rule obsolete but so as long as it gives you the right answer who cares?
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    (Original post by Lord Nutter)
    You didn't answer the full question though.

    The OP asked how to differentiate it and you left it at the simplified version - assuming that the OP knew what to do. Sure quotient rule obsolete but so as long as it gives you the right answer who cares?
    I'm not here to give full solutions to questions, my simplification was a hint (though it pretty much answers the whole question anyway). Read the forum guidelines.

    It's important because there is a difference between taking 5 seconds to answer the question, and taking 30+ seconds. You should always seek an easier way to answer the question rather than jump straight in with brute force.
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    (Original post by Lord Nutter)
    You didn't answer the full question though.

    The OP asked how to differentiate it and you left it at the simplified version - assuming that the OP knew what to do. Sure quotient rule obsolete but so as long as it gives you the right answer who cares?
    no point doing the whole question otherwise they don't learn anything.

    Yh you can use the quotient rule but maths is like coding; it should be simple and clean, free of any unnecessary junk. It also demonstrates whether you can actually see things 'out of the box' instead of 'i see a fraction, use quotient rule'
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    (Original post by RDKGames)
    I'm not here to give full solutions to questions, my simplification was a hint (though it pretty much answers the whole question anyway). Read the forum guidelines.

    It's important because there is a difference between taking 5 seconds to answer the question, and taking 30+ seconds. You should always seek an easier way to answer the question rather than jump straight in with brute force.
    Listen mate all I'm trying to do is help people out and learn myself by doing so. I don't see how leaving a question half answered is helping, what if the OP knew that you had to simplify the answer down to x/2 but didn't know what to do then? Hence quotient/product rule are both acceptable ways of getting the answer.

    I don't see how or why there is a problem about that.

    Also for the record I did have a glimpse through the forum guidelines and I didn't see anything written there saying "you must leave a question half answered or you will be punished"
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    (Original post by Lord Nutter)
    Listen mate all I'm trying to do is help people out and learn myself by doing so. I don't see how leaving a question half answered is helping, what if the OP knew that you had to simplify the answer down to x/2 but didn't know what to do then? Hence quotient/product rule are both acceptable ways of getting the answer.

    I don't see how or why there is a problem about that.

    Also for the record I did have a glimpse through the forum guidelines and I didn't see anything written there saying "you must leave a question half answered or you will be punished"
    It's not useful to just blatantly state the answer and nothing more, nevertheless use a silly method. They might as well just post all their homework questions otherwise...
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    (Original post by Lord Nutter)
    Listen mate all I'm trying to do is help people out and learn myself by doing so. I don't see how leaving a question half answered is helping
    It prods them to actually have a good think about it and get used to solving problems on their own. It's not like they're going to be handheld in exams.

    what if the OP knew that you had to simplify the answer down to x/2 but didn't know what to do then?
    I think if that's the case then I worry whether OP is ready enough to even encounter the quotient rule. Differentiating ax is perhaps literally the easiest and most straight-forward case you encounter at the start of C1.

    Hence quotient/product rule are both acceptable ways of getting the answer.

    I don't see how or why there is a problem about that.
    Nobody says it's a problem. I'm just saying it's useful to have a think about the problem rather than sledgehammering it with an unnecessary rule just because it's a fraction.

    Also for the record I did have a glimpse through the forum guidelines and I didn't see anything written there saying "you must leave a question half answered or you will be punished"
    The jist you need to get out of the rules is that providing hints/starting people off is much better than providing a full solution.
 
 
 
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