C++ Reference Manual

C++ Library Function <cmath>

C ++tan() Function Usage and Example

This function returns the tangent value of the angle (parameter) in radians as returned by the tan() function in<cmath>defined in the header file.

[Math] tan x = tan(x)

tan() prototype (from C ++ 11standard starting)

double tan(double x);
float tan(float x);
long double tan(long double x);
double tan(T x);　//is of integer type

tan() parameter

The tan() function takes a mandatory parameter in radians (can be positive, negative, or 0).

The return value of tan()

The tan() function returns[-∞, ∞]values within the range.

Example1：How does tan() work in C ++What is working in it?

#include <iostream>
#include <cmath>
using namespace std;
int main()
{　
　　long double x = 0.99999, result;
　　result = tan(x);
　　cout << "tan(x) = " << result << endl;
　　
　　double xDegrees =　60.0;
　　//Utilize the tan() function to convert degrees to radians
　　result = tan(xDegrees*3.14159/180);
　　cout << "tan(x) = " << result << endl;
　　return 0;
}

When running the program, the output is:

tan(x) =　1.55737
tan(x) =　1.73205

Example2: tan() function with integer type

#include <iostream>
#include <cmath>
using namespace std;
int main()
{
　　long int x =　6;
　　double result;
　　result = tan(x);
　　cout << "tan(x) = " << result;
　　
　　return 0;
}

When running the program, the output is:

tan(x) =　-0.291006

　C++ Library Function <cmath>