# shz_inv_sqrtf

Source: https://sh4zam.com/api/scalar/shz_inv_sqrtf/

> Calculates 1.0f/sqrtf( x ), using a fast approximation, while safely protecting against division-by-zero

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

Calculates 1.0f/sqrtf( `x` ), using a fast approximation, while safely protecting against division-by-zero.

## Parameters

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

## Returns

`float`

## Availability

- **C++ equivalent:** [`shz::inv_sqrtf`](https://sh4zam.com/api/cpp/#shzinv_sqrtf)
- **Type-generic form:** none
- **Back-ends:** SH4: shared C implementation · SW: portable C · SPU: shared C implementation
- **Defined in:** [`sh4zam/shz_scalar.h:280`](https://github.com/gyrovorbis/sh4zam/blob/ba1e30c88d49df0311870b229e1dd860ef26c477/include/sh4zam/shz_scalar.h#L280)
- **Module:** [Scalar](https://sh4zam.com/api/scalar/), section "FSRRA"