# Derivative -sinx

1. Aug 17, 2008

### Sakha

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. Aug 17, 2008

### Cvan

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.

3. Aug 17, 2008

### Sakha

Thanks i got it

Last edited: Aug 17, 2008
4. Aug 17, 2008

### Cvan

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