ACOS

All functions > MATH > ACOS

Returns the arccosine (inverse cosine) of a number in radians.

Signatures

Returns: Arccosine in radians (between 0 and π)

ACOS(number: T) → DOUBLE

Notes

• Input must be in the range [-1, 1]
• Returns values in the range [0, π] radians
• ACOS(1) = 0, ACOS(-1) = π, ACOS(0) = π/2
• Returns NULL if input is NULL
• Returns NaN for inputs outside [-1, 1]
• Inverse of COS function: ACOS(COS(x)) = x for x in [0, π]

Examples

SELECT
    f1 := ACOS(1.0e0),  -- Arccosine of 1
    f2 := ACOS(0.5e0),  -- Arccosine of 0.5 (60 degrees)
    f3 := ACOS(0.0e0),  -- Arccosine of 0 (90 degrees)
    f4 := ACOS(-1.0e0)  -- Arccosine of -1 (180 degrees)
;