--- layout: stdlib-reference --- # rsqrt ## Description Reciprocal of square root. ## Signature
T rsqrt<T>(T x)
where T : __BuiltinFloatingPointType;
vector<T, N> rsqrt<T, N:int>(vector<T, N> x)
where T : __BuiltinFloatingPointType;
matrix<T, N, M> rsqrt<T, N:int, M:int>(matrix<T, N, M> x)
where T : __BuiltinFloatingPointType;
## Generic Parameters
#### T: [\_\_BuiltinFloatingPointType](../interfaces/0_builtinfloatingpointtype-029hm/index.html)
#### N : int
#### M : int
## Parameters
#### x : [T](rsqrt.html#typeparam-T)
The value to compute the reciprocal square root of.
#### x : [vector](../types/vector/index.html)\<[T](../types/vector/index.html#typeparam-T), [N](../types/vector/index.html#decl-N)\>
The value to compute the reciprocal square root of.
#### x : [matrix](../types/matrix/index.html)\<[T](../types/matrix/t-0.html), [N](../types/matrix/index.html#decl-N), [M](../types/matrix/index.html#decl-M)\>
The value to compute the reciprocal square root of.
## Return value
The reciprocal square root of x.
## Availability and Requirements
Defined for the following targets:
#### hlsl
Available in all stages.
#### glsl
Available in all stages.
#### cpp
Available in all stages.
#### cuda
Available in all stages.
#### metal
Available in all stages.
#### wgsl
Available in all stages.
#### spirv
Available in all stages.