Question

What is the derivative of `f(x)=sin(-x+pi)-sin(x)`?

Answer 1

`0`

Explanation:

`sin(t+pi) = -sin(t)`

`sin(-t) = -sin(t)`

So:

`f(x) = sin(-x+pi)-sin(x) = -sin(-x)-sin(x)`

`= sin(x)-sin(x) = 0`

and

`d/(dx) 0 = 0`