牛顿—科特斯数值积分

/*sinx [0,pi/2] */#include<stdio.h> #include<math.h>#define N 10010#define e 1e-5#define PI acos(-1)double f(double x){    return sin(x);}double T(double a,double b){       return (b-a)/2*(f(a)+f(b));}double S(double a,double b) {       return (b-a)/6*(f(a)+4*f((a+b)/2)+f(b));}double C(double a,double b){    double c1,c2,c3;    c1=(a+b)/2.0;    c2=(a+c1)/2.0;    c3=(c1+b)/2.0;    return (b-a)/90*(7*f(a)+32*f(c2)+12*f(c1)+32*f(c3)+7*f(b));}int main() {    double a=0,b=PI/2.0;    double t,s,c;    t=T(a,b);s=S(a,b);c=C(a,b);    printf("梯形求积=%lf:\n",t);    printf("辛普森求积=%lf:\n",s);    printf("科特斯求积=%lf:\n",c);    return 0;}