c语言泰勒展开式sin,【C++ 程序】 sin(x)的泰勒展开

C++是如何计算sin(x)的呢？其实使用泰勒展开来算的。下面不直接调用sin(x)来写一下程序：

程序

#include

using namespace std;

constexpr double pi = 3.1415926535897932384625;

double ret = 1;

long double _fac(long double num1)

{

ret /= num1;

if (num1 == 1)

return ret;

else return _fac(num1 - 1);

}

double my_sin(double num)

{

while (num > pi)

num -= pi;

while (num < -pi)

num += pi;

double ret = 0;

double sign = 1;

for (double i = 1; i <= 99; i += 2)

{

ret += sign * pow(num, i) * _fac(i);

sign = -sign;

::ret = 1; // call the global ret

}

return ret;

}

int main()

{

double n;

cin >