C++ acos()用法及代碼示例

acos()是C++ STL中的內置函數，該函數返回弧度數(參數)的反餘弦值。 acos()函數返回的值始終位於– $\pi$ 到+ $\pi$

用法:

acos(data_type x)

參數：此函數接受一個強製性參數x，該參數指定應計算其反餘弦值的值。它必須介於-1和+1之間，否則將拋出域錯誤(範圍錯誤)。該參數可以是double，float或long double數據類型。

返回：該函數返回介於– $\pi$ 和+ $\pi$ 。逆時針角度以弧度為單位。

示例1:

// C++ program to demonstrate 
// the acos() function 
#include <bits/stdc++.h> 
using namespace std; 
  
int main() 
{ 
    double x = 1.0; 
  
    // Function call to calculate acos(x) value 
    double result = acos(x); 
  
    cout << "acos(1.0) = " << result << " radians" << endl; 
    cout << "acos(1.0) = " << result * 180 / 3.141592 
         << " degrees" << endl; 
  
    return 0; 
}

輸出：

acos(1.0) = 0 radians
acos(1.0) = 0 degrees

示例2:

// C++ program to demonstrate 
// the acos() function 
#include <bits/stdc++.h> 
using namespace std; 
  
int main() 
{ 
    double result; 
    int x = -1; 
  
    // Function call to calculate acos(x) value 
    result = acos(x); 
  
    cout << "acos(-1) = " << result 
         << " radians" << endl; 
    cout << "acos(-1) = " << result * 180 / 3.141592 
         << " degrees" << endl; 
  
    return 0; 
}

輸出：

acos(-1) = 3.14159 radians
acos(-1) = 180 degrees

錯誤和異常：

當字符串或字符作為參數傳遞時，該函數不返回任何匹配函數來調用錯誤。
當傳遞超出範圍的數字作為參數時，該函數將返回nan。

以下示例程序旨在說明上述方法的錯誤和異常：

示例3:

// C++ program to demonstrate the acos() 
// function errors and exceptions 
#include <bits/stdc++.h> 
using namespace std; 
  
int main() 
{ 
    double result; 
    string x = "gfg"; 
    result = acos(x); 
  
    cout << "acos(x) = " << result 
         << " radians" << endl; 
    cout << "acos(x) = " << result * 180 / 3.141592 
         << " degrees" << endl; 
  
    return 0; 
}

輸出：

prog.cpp:10:17: error: no matching function for call to 'acos(std::__cxx11::string&)'
  result = acos(x);

示例4:

// C++ program to demonstrate the 
// acos() function errors and exceptions 
#include <bits/stdc++.h> 
using namespace std; 
  
int main() 
{ 
    double x = 3.7, result; 
  
    // Function call to calculate acos(x) value 
    result = acos(x); 
  
    cout << "acos(3.7) = " << result 
         << " radians" << endl; 
    cout << "acos(3.7) = " << result * 180 / 3.141592 
         << " degrees" << endl; 
  
    return 0; 
}

輸出：

acos(3.7) = nan radians
acos(3.7) = nan degrees

相關用法

注：本文由純淨天空篩選整理自pawan_asipu大神的英文原創作品 acos() function in C++ STL。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。