ACOS

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Syntax

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Scalar

acos(value)

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Arguments

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Returns

• Type: DOUBLE; FLOAT when the input is evaluated as FLOAT
• Possible values: Values in radians from 0 through pi for input in [-1, 1]; NaN outside this domain.
• NULL behavior: Returns NULL when an argument is NULL.

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Properties

• Approximation bound: No fixed maximum error is guaranteed.

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Units

• Input unit: Dimensionless number
• Output unit: Radians
• Use degrees(result) to convert the result to degrees.

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Usage notes

• Numeric inputs are normally converted to DOUBLE for calculation. An input evaluated as FLOAT keeps FLOAT precision.
• INTEGER and INT mean the same type; STRING means VARCHAR text. NULL can be used with a supported type. Cast NULL explicitly when its type would otherwise be unclear.
• Exact result: Floating-point computation can round the mathematical result.

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Examples

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Value and NULL input

SELECT acos(CAST(1 AS DOUBLE)) AS "value", acos(CAST(NULL AS DOUBLE)) AS null_value;

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Zero and the lower input boundary

SELECT round(acos(CAST(0 AS DOUBLE)), 6) AS at_zero, round(acos(CAST(-1 AS DOUBLE)), 6) AS at_minus_one;

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Limitations

• Input outside [-1, 1] produces NaN rather than NULL.
• Query tools may report DOUBLE even when the result is FLOAT. The reported type does not increase the result’s precision.

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Related functions

• radians
• degrees