---
title: "acos(_:)"
framework: simd
role: symbol
role_heading: Function
path: "simd/acos(_:)-9k95t"
---

# acos(_:)

Returns the arccosine of each element in a vector.

## Declaration

```swift
func acos(_ x: simd_float16) -> simd_float16
```

## See Also

### Trigonometric Functions

- [asin(_:)](simd/asin(_:)-52bly.md)
- [atan(_:)](simd/atan(_:)-7y100.md)
- [atan2(_:_:)](simd/atan2(_:_:)-5dweo.md)
- [cos(_:)](simd/cos(_:)-40gvn.md)
- [cospi(_:)](simd/cospi(_:)-7kfdh.md)
- [sin(_:)](simd/sin(_:)-7e17y.md)
- [sinpi(_:)](simd/sinpi(_:)-6d2hq.md)
- [sincos(_:)](simd/sincos(_:)-go67.md)
- [sincospi(_:)](simd/sincospi(_:)-h3av.md)
- [tan(_:)](simd/tan(_:)-5q9ad.md)
- [tanpi(_:)](simd/tanpi(_:)-2vht8.md)