The position of a particle is s(t)=sin(t)+cos(t)s(t) = \sin(t) + \cos(t)s(t)=sin(t)+cos(t). At what time t∈[0,π]t \in [0, \pi]t∈[0,π] is the velocity zero?
\pi/4
\pi/2
\pi/3
3\pi/4