Greatest value of the acceleration?

Question

A particle moves in a straight line so that, at time t s after passing a fixed point O, its velocity is v m/s,

where v = 6t + 4 cos 2t. Find the greatest value of the acceleration.

Answer 1

Acceleration is the time derivative of velocity. The time derivative of that expression is 6 - 8sin(2t). The maximum value is 6 + 8 = 14 m/s^2