C语言求定积分∫sinxdx,∫cosxdx,∫e^xdx的值
说明：sin,cos,exp已在系统的数学函数库中，程序开头要用#include<math.h>.代码如下：#include<stdio.h>#include<math.h>float integral(float (*)(float),float,float,int);float fsin(float);float fcos(float);float fexp(float);int main(){float a1,b1,a2,b2,a3,b3,c,(*p)(float);int n=10;printf("input a1,b1:");scanf("%f%f",&a1,&b1);//sinx定积分上下限printf("input a2,b2:");scanf("%f%f",&a2,&b2);//cosx定积分上下限printf("input a3,b3:");scanf("%f%f",&a3,&b3);//e^x定积分上下限p=fsin;//p指向fsin函数c=integral(p,a1,b1,n);//求出sinx的定积分printf("The integral of sin(x) is:%f\n",c);p=fcos;c=integral(p,a2,b2,n);printf("The integral of cos(x) is:%f\n",c);p=fexp;c=integral(p,a3,b3,n);printf("The integral of cos(x) is:%f\n",c);return 0;}//求定积分的代码float integral(float(*p)(float),float a,float b,int n){int i;float x,h,s;h=(b-a)/n;x=a;s=0;for(i=1;i<=n;i++){x=x+h;//x+=h;s=s+(*p)(x)*h;//s+=(*p)(x)*h;}return (s);}//sinx,cosx,e^xfloat fsin(float x){return sin(x);}float fcos(float x){return cos(x);}float fexp(float x){return exp(x);}
运行结果如图：
