# Erfcx

Erfcx-func

## Definition:

The **y = erfcx(***x*) function is the scaled complementary error function, defined as

where **erfc(x)** is the complementary error function.

When x is very large, erfcx(x) is approximately .

## Parameters:

- x (input, double)
- The argument x of the function.
- y (output, double)
- The approximate value of the scaled complementary error function.