Function acos() calculates the radian of a cosine value.

Arguments：

• Cosine <number>, ∈ [-1, 1]

Returns：

• Radian <number>, ∈ [-PI/2, PI/2]

Common Usage

Example: calculate the radian of the cosine value 0.5

return acos(0.5) * 180 / pi()

Example: calculate the radians of a column of cosine values

uncollect [1, -0.5, 0] as a
return acos(a)