C++ Math tgamma
The tgamma function computes the gamma function of an argument passed to the function.
Suppose a number is x:
Syntax
float tgamma(float x);
double tgamma(double x);
long double tgamma(long double x);
double tgamma(double x);
Parameter
x : It is a floating point value.
Return value
It returns the gamma function value of x.
| Parameter | Return value |
|---|---|
| x = ±0 | ±∞ |
| x = -ve | nan |
| x = -∞ | nan |
| x = +∞ | +∞ |
| x = nan | nan |
Example 1
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<<"tgamma(x) : "<<tgamma(x);
return 0;}
Output:
Value of x is : 0
tgamma(x) : inf
In the above example, the value of x is zero.Therefore, the function tgamma returns +∞.
Example 2
Let's see the simple example when the value of x is negative.
#include <iostream>
#include<math.h>
using namespace std;
int main()
{
int x= -6;
cout<<"Value of x is : "<<x<<'\n';
cout<<"tgamma(x) : "<<tgamma(x);
return 0;
}
Output:
Value of x is : -6
tgamma(x) : nan
In the above example, the value of x is a negative integer. Therefore, the function tgamma returns nan.
Example 3
Let's see the simple example when the value of x is -∞.
#include <iostream>
#include<math.h>
using namespace std;
int main()
{
float x= -9.0/0.0;
cout<<"Value of x is : "<<x<<'\n';
cout<<"tgamma(x): "<<tgamma(x);
return 0;
}
Output:
Value of x is : -inf
tgamma(x): nan
In the above example, the value of x -∞. Therefore, the function tgamma returns nan.
Example 4
Let's see the simple example when the value of is +∞.
#include <iostream>
#include<math.h>
using namespace std;
int main()
{
float x= 7.8/0.0;
cout<<"Value of x is : "<<x<<'\n';
cout<<"tgamma(x) : "<<tgamma(x);
return 0;
}
Output:
Value of x is : inf
tgamma(x) : inf
In the above example, the value of x is +∞. Therefore, the function tgamma returns +∞.
Example 5
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<<"tgamma(x) : "<<tgamma(x);
return 0;
}
Output:
Value of x is : -nan
tgamma(x) : -nan
In the above example, the value of x is nan. Therefore, the function tgamma returns nan.