龙贝格法求积分c语言程序,矩形法，梯形法，辛普生法，科特斯法，龙贝格法，求定积分C语言源代码...

*

矩形法，梯形法，辛普生法，科特斯法，龙贝格法 ，对 y=x*x 求定积分

版本：1.0

*/

#include

#include

void

print();

int

main()

{

long

n;

double

a,b;

printf("请输入积分下限,积分上限,步数：");

scanf("%lf,%lf,%d",&a,&b,&n);

if(n<0)exit(0);

print(a,b,n);

//

system("pause");

return(0);

}

void

print(double a,double b, long n)

{

double

Rn(double a,double b, long n);

double

Cn(double a,double b, long n);

double

Sn(double a,double b, long n);

double

Tn(double a,double b, long n);

double

Jn(double a,double b, long n);

printf("\n================================================================================\n");

printf("函数X

* X在积分下限是%f，积分上限是%f，步长是%d的积分近似值是：\n",a,b,n);

printf("--------------------------------------------------------------------------------\n");

printf("矩形法的近似值为：.9f\n",Jn(a,b,n));

printf("梯形法的近似值为：.9f\n",Tn(a,b,n));

printf("辛普生法的近似值：.9f\n",Sn(a,b,n));

printf("科特斯法的近似值：.9f\n",Cn(a,b,n));

printf("龙贝格法的近似值：.9f\n",Rn(a,b,n));

printf("================================================================================\n");

}

double Rn(double a,double b, long n)

{

double

Cn(double a,double b, long n);

double

Rn;

Rn=(64*Cn(a,b,2*n)-Cn(a,b,n))/63;

return(Rn);

}

double Cn(double a,double b, long n)

{

double

Sn(double a,double b, long n);

double

Cn;

Cn=(16*Sn(a,b,2*n)-Sn(a,b,n))/15;

return(Cn);

}

double Sn(double a,double b, long n)

{

double

Tn(double a,double b, long n);

double

Sn;

Sn=(4*Tn(a,b,2*n)-Tn(a,b,n))/3;

return(Sn);

}

double Tn(double a,double b, long n)

{

double

F(double x);

int

i;

double

h,Tn;

h=(b-a)/n;

Tn=(F(a)+F(b))/2;

for(i=1;i

{

Tn=Tn+F(a+i*h);

}

Tn=Tn*h;

return

(Tn);

}

double Jn(double a,double b, long n)

{

double

F(double x);

int

i;

double

h,Jn=0.0;

h=(b-a)/n;

for(i=1;i

{

Jn+=F(a+i*h+h/2);

}

Jn=Jn*h;

return

(Jn);

}

double F(double x)

{

double

F;

F=x*x;

return(F);

}