Some questions about autocorrelation

for the sine function

The starting point of the function after autocorrelation must be the maximum value

Then the maximum value of the autocorrelation function must be the point where the maximum value of the original function is multiplied by the maximum value

The minimum value of the autocorrelation function is the case where the maximum value of the original function is multiplied by the minimum value

Therefore, the time corresponding to (from the origin to the position where the first highest peak passes after) is the period of the original function