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Derivative -sinx

  1. Aug 17, 2008 #1
    I know the derivative of cos(x) = -sinx
    is the derivative of -sinx= cosx
    or maybe derivative of -sinx = 1/cosx
    which is it
     
  2. jcsd
  3. Aug 17, 2008 #2
    Derivative of sin(x) is cos(x).
    Derivative of (-1)*(sin(x))= (-1) (cos(x))
    The - is just a constant you can take out front.
     
  4. Aug 17, 2008 #3
    Thanks i got it
     
    Last edited: Aug 17, 2008
  5. Aug 17, 2008 #4
    With respect to some variable, the derivative of a constant is zero. However by recognizing (-1) as a constant multiple while taking the derivative of a function of a variable with respect to that variable, you can write:
    d/dx((-1)(f(x))= (-1) d/dx(f(x)) = (-1) (f'(x)

    Edit: http://en.wikipedia.org/wiki/Table_of_derivatives
    See: Linearity
     
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