# Arccos > Supported in: Batch, Faster, Streaming Inverse cosine function. **Expression categories:** Numeric ## Declared arguments * **Angle unit:** Output angle unit which is either degrees or radians.
*Enum\* * **Value:** The value to compute arccos on.
*Expression\* **Output type:** *Double* ## Examples ### Example 1: Base case **Argument values:** * **Angle unit:** `radians` * **Value:** 1.0 **Output:** 0.0 *** ### Example 2: Null case **Argument values:** * **Angle unit:** `radians` * **Value:** *null* **Output:** *null* ***