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Homework Help: Find Devivaties with respect to x:

  1. Sep 9, 2012 #1
    Find Devivaties with respect to x:

    1). y=sin(cos(x+3));

    2). tan(x+y)=ln x+ 5y.

    heres my work...just need a double check

    1). y=sin(cos(x+3));

    2). tan(x+y)=ln x+ 5y.

    1:y = sin(cos(x+3))
    y' = cos(cos(x+3))(-sin(x+3))(1)
    y' = {-sin(x+3)}{cos(cos(x+3))}

    2. Tan(x+y) = lnx+5y
    Sec^2(x+y)(1+y') = 1/x + 5yy'
    y' = {((1/x))-(Sec^2(x+y))}/(Sec^2(x+y) - 5y)
     
  2. jcsd
  3. Sep 9, 2012 #2
    You messed up in deriving 5y on problem 2. (5y)' = 5y'. Not 5yy'. Everything else prior is correct and so is problem 1.
     
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