I want to find the Square root of something, but which header file would I need to include for Sqrt() to work please?

Like this:

```
float RightStickThreshold = Sqrt((aTurn * 2) + (aLookup * 2));
```

Thanks

I want to find the Square root of something, but which header file would I need to include for Sqrt() to work please?

Like this:

```
float RightStickThreshold = Sqrt((aTurn * 2) + (aLookup * 2));
```

Thanks

It is in Fmath::Sqrt

```
static FORCEINLINE float Sqrt( float Value ) { return sqrtf(Value);
```

Btw it is not in the docs for some reason. Does anyone know why?

Thanks maikklein but its not working how I’d like. I basically want to see if a player has pushed far enough away from the centre of the right joystick. Say about half way.

```
void ATutorialCodeCharacter::TurnAtRate(float Value)
{
aTurn = Value;
}
void ATutorialCodeCharacter::LookUpAtRate(float Value)
{
aLookup = Value;
}
void ATutorialCodeCharacter::Tick(float DeltaTime)
{
float MaxThresholdForRotating = 150;
float RightStickThreshold = FMath::Sqrt((aTurn * 2) + (aLookup * 2));
if (RightStickThreshold >= MaxThresholdForRotating)
{
bRotating = true;
}
}
```

When I debug RightStickThreshold I get a strange value. In some areas on the joystick I get a value of -1.#1ND00

Any suggestions please?

Thanks

Most likely scenarios is that you’re getting an [FONT=Courier New]NaN. This happens if you try to get the square root of a negative number, or of zero, both of which are valid inputs for axes. Make threshold use the absolute values of [FONT=Courier New]aTurn and [FONT=Courier New]aLookup, and if [FONT=Courier New]aTurn and [FONT=Courier New]aLookup are both 0.0, then just set threshold to 0.0 instead of attempting the calculation.

Thanks jeff_lamarche that fixed it