Question

在这个程序中，我被迫为3个trig函数“sind，cosd，tand”调用函数，我必须调用它们到主程序。我对如何让它们发挥作用毫无头绪。我还必须以度为单位输入值。我也不知道'while'语句应该是什么。非常感谢任何提示。

#include <iostream>
#include <cmath>
#include <iomanip>

double sind();

int main(void)
{
double s, c, t;

char select;

    std::cout << "Trigonometric functions in degrees." << std::endl     << std::endl;
    std::cout << "Please select a funcion to be performed : " <<     std::endl << std::endl;


do
{
    std::cout << "S/s: sin, " << "C/c: cos, " << "T/t: tan, " <<     "E/e: Exit" << std::endl;
    std::cout << "please enter your selection. \n";
    std::cin >> select;

    switch (select)
    {
        case 'S' : case 's':
            std::cout << "Please enter a value in degrees : ";
            std::cin >> s;
            std::cout << "sin(" << s << " degrees" << ")" << "=" <<     sind << std::endl;
            break;
        case 'C' : case 'c':
            std::cout << "Please enter a value in degrees : ";
            std::cin >> c;
            std::cout << "cos(cos) : " << "cosd "<< std::endl;
            break;
        case 'T' : case 't':
            std::cout << "Please enter a value in degrees : ";
            std::cin >> t;
            std::cout << "tan(tan) : " << "tand" << std::endl;
            break;
        case 'E' : case 'e' :
            std::cout << "Program has terminated. Goodbye." <<     std::endl;
            break;
        default:
            std::cout << "You have entered an invalid code. Please     try again." << std::endl;
        }
} while (select != 'e');
}

Answer 1

正如@FrançoisAndrieux所说，你应该真正了解函数在C ++中是如何工作的。以下是您的具体问题的一些帮助：要以度为单位计算角度的正弦值，必须先将其转换为弧度：

double s_rad = s / 180 * PI;

您必须在include语句和主函数的开头之间定义Pi

#define PI 3.14159265

然后，您可以通过将其写入函数名称后面的括号中来将此值传递给函数：

double result = sin ( s_rad );

或直接

double result = sin (s / 180 * PI);

如何正确地制作三角函数的调用函数

1 个答案: