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Homework Help: Simple Derivative Question

  1. Mar 15, 2007 #1
    Sorry for not using JavaScript or whatever script is needed, I don't have enough time to figure it out b/c my class is soon... anyways I just need to know know to find the derivative of 3 groups of parentheses

    (x+3)(x-4)(x+5)

    I've tried using the product rule on the first two and then using the rule on the result from that and (x+5) but it's not working. I'm an idiot.. thanks for any help.
     
  2. jcsd
  3. Mar 15, 2007 #2
    It's a simple extension of the product rule: (uvw)' = u'vw + uv'w + uvw', where u,v and w are functions of x.
     
  4. Mar 15, 2007 #3
    okay thanks a lot
     
  5. Mar 15, 2007 #4
    That should work actually.
    If you call the 3 functions u(x), v(x) and w(x) and let y(x) = u(x)v(x), then [y(x)w(x)]' = y'w + yw'. Just replace y = uv and y' = u'v + uv', you get (u'v + uv')w + uvw' = u'vw + uv'w + uvw', which is exactly what neutrino.
     
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