# shz_atanf_q1

Source: https://sh4zam.com/api/trig/shz_atanf_q1/

> Fast arctangent approximation for values lying within the first quadrant (>= 0.0f)

```c
SHZ_INLINE float shz_atanf_q1(float x) SHZ_NOEXCEPT;
```

Fast arctangent approximation for values lying within the first quadrant (`>= 0.0f`).

## Parameters

| Name | Type | Description |
| --- | --- | --- |
| `x` | `float` |  |

## Returns

`float`

## Availability

- **C++ equivalent:** [`shz::atanf_q1`](https://sh4zam.com/api/cpp/#shzatanf_q1)
- **Type-generic form:** none
- **Back-ends:** SH4: shared C implementation · SW: portable C · SPU: shared C implementation
- **Defined in:** [`sh4zam/shz_trig.h:151`](https://github.com/gyrovorbis/sh4zam/blob/ba1e30c88d49df0311870b229e1dd860ef26c477/include/sh4zam/shz_trig.h#L151)
- **Module:** [Trigonometry](https://sh4zam.com/api/trig/), section "Inverse Functions"