1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?