2421: C語言習題 矩形法求定積分
時間限制: 1 Sec
記憶體限制: 128 MB
送出: 354
解決: 234
題目描述
寫一個用矩形法求定積分的通用函數,分别求
(說明: sin,cos,exp已在系統的數學函數庫中,程式開頭要用#include<cmath>)。
輸入
輸入求sin(x) 定積分的下限和上限
輸入求cos(x) 定積分的下限和上限
輸入求exp(x) 定積分的下限和上限
輸出
求出sin(x)的定積分
求出cos(x)的定積分
求出exp(x)的定積分
樣例輸入
0 1
0 1
0 1
樣例輸出
The integral of sin(x) is :0.48
The integral of cos(x) is :0.83
The integral of exp(x) is :1.76
提示
主函數已給定如下,送出時不需要包含下述主函數
/* C代碼 */
int main()
{
float integral(float (*p)(float),float a,float b,int n);
float a1,b1,a2,b2,a3,b3,c,(*p)(float);
float fsin(float);
float fcos(float);
float fexp(float);
int n=20;
scanf("%f%f",&a1,&b1);
scanf("%f%f",&a2,&b2);
scanf("%f%f",&a3,&b3);
p=fsin;
c=integral(p,a1,b1,n);
printf("The integral of sin(x) is :%.2f\n",c);
p=fcos;
c=integral(p,a2,b2,n);
printf("The integral of cos(x) is :%.2f\n",c);
p=fexp;
c=integral(p,a3,b3,n);
printf("The integral of exp(x) is :%.2f\n",c);
return 0;
}
/* C++代碼 */
int main()
{
float integral(float (*p)(float),float a,float b,int n);
float a1,b1,a2,b2,a3,b3,c,(*p)(float);
float fsin(float);
float fcos(float);
float fexp(float);
int n=20;
cin>>a1>>b1;
cin>>a2>>b2;
cin>>a3>>b3;
cout<<setiosflags(ios::fixed);
cout<<setprecision(2);
p=fsin;
c=integral(p,a1,b1,n);
cout<<"The integral of sin(x) is :"<<c<<endl;
p=fcos;
c=integral(p,a2,b2,n);
cout<<"The integral of cos(x) is :"<<c<<endl;;
p=fexp;
c=integral(p,a3,b3,n);
cout<<"The integral of exp(x) is :"<<c<<endl;
return 0;
}
迷失在幽谷中的鳥兒,獨自飛翔在這偌大的天地間,卻不知自己該飛往何方……
#include <stdio.h>
#include <math.h>
float integral(float (*p)(float),float a,float b,int n)
{
float s=0.0,i,w;
w=(b-a)/n;
for(i=a; i<=b; i+=w)
s+=p(i+w)*w;
return s;
}
float fsin(float a)
{
return sin(a);
}
float fcos(float a)
{
return cos(a);
}
float fexp(float a)
{
return exp(a);
}
int main()
{
float integral(float (*p)(float),float a,float b,int n);
float a1,b1,a2,b2,a3,b3,c,(*p)(float);
float fsin(float);
float fcos(float);
float fexp(float);
int n=20;
scanf("%f%f",&a1,&b1);
scanf("%f%f",&a2,&b2);
scanf("%f%f",&a3,&b3);
p=fsin;
c=integral(p,a1,b1,n);
printf("The integral of sin(x) is :%.2f\n",c);
p=fcos;
c=integral(p,a2,b2,n);
printf("The integral of cos(x) is :%.2f\n",c);
p=fexp;
c=integral(p,a3,b3,n);
printf("The integral of exp(x) is :%.2f\n",c);
return 0;
}