C++ Math erf()

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

$C++ Math erf() function$

Syntax

Suppose a number is 'x':

float erf( float x);
double erf( double x);
long double erf( long double x);
double erf( integral 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.

#include <iostream>
#include<math.h>
using namespace std;
int main()
{
     double x= 6.2;
     cout<<"Value of x is : "<<x<<'\n';
     cout<<"erf(x) : "<<erf(x);
     return 0;}

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.

#include <iostream>
#include<math.h>
using namespace std;
int main()
{
     double x= 1.0/0.0;
     cout<<"Value of x is : "<<x<<'\n';
     cout<<"erf(x) : "<<erf(x);
     return 0;
}

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.

#include <iostream>
#include<math.h>
using namespace std;
int main()
{
     float x= 0.0;
     cout<<"Value of x is : "<<x<<'\n';
     cout<<"erf(x) : "<<erf(x);
     return 0;
}

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.

#include <iostream>
#include<math.h>
using namespace std;
int main()
{
     float x= 0.0/0.0;
     cout<<"Value of x is : "<<x<<'\n';
     cout<<"erf(x) : "<<erf(x);
     return 0;
}

Output: