用函数实现：精确求余弦函数近似值，误差控制有妙招！

```c #include <stdio.h> #include <math.h> double funcos( double e, double x ) { double term = 1; double sum = 0; int n = 0; while (fabs(term) >= e) { double factorial = 1; int i; for (i = 1; i <= 2 * n; i++) { factorial *= i; } term = pow(-1, n) * pow(x, 2 * n) / factorial; sum += term; n++; } return sum; } ``` ######[AI问答 | 153点数解答 | 2025-12-10 23:08:46]