#include<stdio.h>
#include<math.h>



void main(){
	double (*t[3])(double);

	t[0] = sin;
	t[1] = cos;
	t[2] = tan;

	printf("sin(20) = %lf\n", sin(20));

	for(int i = 0; i < 3; i++)
		printf("t[%d](20) = %lf\n", i, t[i](20));
}