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Homework Help: Xy + sqrt[sin(6x)*ln(x)]?

  1. Mar 2, 2012 #1
    xy.. product rule

    product rule for the rest,

    f' cos6
    g' 1/x

    f'g*g'f + (xy)<- part I get confused with..
     
  2. jcsd
  3. Mar 2, 2012 #2

    Mark44

    Staff: Mentor

    Product rule and chain rule.
    No, you need the chain rule first, since there's a composite function, √(sin(6x) * ln(x)), with a product inside.
    What is f' cos6 supposed to mean? If this is supposed to mean the derivative of cos(6x), it's wrong.

    For the 2nd line, I get what you're doing, but you're not using the notation well.
    d/dx(ln(x)) = 1/x
    That gets across the idea that you're differentiating ln(x), and that the derivative is 1/x.

    Another way to say it is, if g(x) = ln(x), then g'(x) = 1/x.
     
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