The instantaneous displacement of a simple pendulum oscillator is given by x=Acosωt+π4. Its speed will be maximum at time
π4ω
π2ω
πω
2πω
V=dxdt=−Aωsinωt+π45, Vmax=Aω
when V=Vmax, ωt+π4=π2,3π2,5π2,7π2,....
∴ t=1ωπ2−π4=π4ω