A simple harmonic motion of an object with a period of 4S and an amplitude of 2cm, from t / 8 to t, the distance of the particle motion is 7cm

A simple harmonic motion of an object with a period of 4S and an amplitude of 2cm, from t / 8 to t, the distance of the particle motion is 7cm

Because it is not a uniform motion, the distance is not proportional to time, the real result should be smaller than 7cm, because the starting T / 8 speed is larger
The real distance is 6 + (2-2sin (45)) / = 6.6cm;