列写三角函数表（C语言实现）

下面是用函数指针实现的三角函数表，其中cos函数、sin函数和tan函数都已经在<math.h>中定义，函数tabulate中使用的函数ceil也属于<math.h>，当给定double型实参x时，函数ceil会返回大于或等于x的最小整数。当给定三角函数的起始值，终止值和步长以后，程序会打印出相对应的三角函数值。

#include <math.h>#include <stdio.h>// 传递函数指针f时，tabulate函数显示函数f的值void tabulate(double (*f)(double), double first, double last, double incr);int main(void){    double initial, final, increment;    printf("Enter initial value: ");    scanf("%lf", &initial);    printf("Enter final value: ");    scanf("%lf", &final);    printf("Enter increment: ");    scanf("%lf", &increment);    printf("\n      x        cos(x)"           "\n   -------    -------\n");    tabulate(cos, initial, final, increment);    printf("\n      x        sin(x)"           "\n   -------    -------\n");    tabulate(sin, initial, final, increment);    printf("\n      x        tan(x)"           "\n   -------    -------\n");    tabulate(tan, initial, final, increment);    return 0;}void tabulate(double (*f)(double), double first, double last, double incr){    double x;    int i, num_intervals;    num_intervals = ceil((last - first) / incr);    for (i = 0; i <= num_intervals; i++) {        x = first + i * incr;        printf("%10.5f %10.5f\n", x, (*f)(x));    }}

参考资料：
《C语言程序设计现代方法》