# C++ Math erf()

The erf() function computes the error function value of a parameter passed to the function.

## Syntax

Suppose a number is 'x':

## Parameter

x: It is a floating point value.

## Return value

It returns the error function value of x.

Parameter Return value
x=±0 ±0
x=± infinite ±1
x=nan nan

## Example 1

Let's see the simple example.

Output:

```Value of x is : 6.2
erf(x) : 1
```

In the above example, value of x is 6.2. The erf() function returns the value i.e 1.

## Example 2

Let's see the simple example when the value of x is infinite.

Output:

```Value of x is : inf
erf(x) : 1
```

In the above example, the value of x is infinite. Therefore, the function erf() returns the value 1.

## Example 3

Let's see the simple example when the value of x is zero.

Output:

```Value of x is : 0
erf(x) : 0
```

In the above example, the value of x is zero. Therefore, the function erf() returns 0 value.

## Example 4

Let's see the simple example when the value of x is nan.

Output:

```Value of x is : -nan
erf(x) : -nan
```

In the above example, the value of x is nan. Therefore, the function erf() returns nan.

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