c++中函数atan

C ++ atan()函数 (C++ atan() function)

atan() function is a library function of cmath header, it is used to find the principal value of the arc tangent of the given number, it accepts a number (x) and returns the principal value of the arc tangent of x in radians.

atan()函数是cmath标头的库函数，用于查找给定数字的反正切的主值，它接受数字( x )并以弧度返回x的反正切的主值。

Syntax of atan() function:

atan()函数的语法：

    atan(x);

Parameter(s): x – is the value whose arc tangent to be calculated.

参数： x –是要计算其反正切值的值。

Return value: double – it returns double type value that is the principal value of the arc tangent of the given number x.

返回值： double-返回double类型值，它是给定数字x的反正切的主要值。

Example:

例：

    Input:
float x = 0.65;
Function call:
atan(x);    
Output:
0.576375

C ++代码演示atan()函数的示例 (C++ code to demonstrate the example of atan() function)

// C++ code to demonstrate the example of 
// atan() function
#include <iostream>
#include <cmath>
using namespace std;
// main() section
int main()
{
float x;
x = -1.0;
cout<<"atan("<<x<<"): "<<atan(x)<<endl;
x = -0.89;
cout<<"atan("<<x<<"): "<<atan(x)<<endl;    
x = 0.65;
cout<<"atan("<<x<<"): "<<atan(x)<<endl;    
x = 1;
cout<<"atan("<<x<<"): "<<atan(x)<<endl;        
return 0;
}

Output

输出量

atan(-1): -0.785398
atan(-0.89): -0.727263
atan(0.65): 0.576375
atan(1): 0.785398

Reference: C++ atan() function

参考： C ++ atan()函数

翻译自: https://www.includehelp.com/cpp-tutorial/atan-function-with-example.aspx

c++中函数atan