RapidTables
arccos 0 = ?
The arccosine is the inverse cosine function.
Since
cos 0 = cos 0º = 1
The arccosine of 0 is equal to the inverse cosine function of 0, which is equal to π/2 radians or 90 degrees:
arccos 0 = cos-1 0 = π/2 rad = 90º