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
x=Acosωt+π4 and v=dxdt=−Aωsinω t+π4
For maximum speed, sin ω t+π4=1 ⇒ω t+π4=π2 or ω t=π2−π4 ⇒t=π4ω