二分法程序清单

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1、1、二分法程序清单：#include#include#includedoublef(doublex){doubley=0;y=sin(x)-x*x/2;returny;}voidmain(){doublea,b,y1,y2,temp;inte1,e2=1,n,i=0;printf("请输入根的区间：");scanf("%lf",&a);scanf("%lf",&b);y1=f(a);y2=f(b);if((y1*y2)<0){printf("要求小数点后的位数：");sc

2、anf("%d",&e1);while(e1>0){e2=e2*10;e1--;}n=(int)(log((b-a)*e2)/log(2));printf("对方程sinx-x2/2=0开始进行二分：");while(n>0){printf("第%d次二分结果:",i);temp=f((a+b)/2);if((f(a)*temp)<0){b=(a+b)/2;printf("a=%f,b=%f",a,b);}if((f(b)*temp)<0){a=(a+b)/2;printf("a=%f,b=%f",a,b);}

3、i++;n--;}}printf("方程的解是：%6.5f",(a+b)/2);}1、迭代法的求根程序清单：#include#include#includedoublef(doublex){doubley=0;y=x*x*x-x-1;returny;}doublefdao(doublex){doublea=1.0/3;returnpow(x+1,a);}voidmain(){doublex1,x2,a,b,e2=1;inti=0,e1;printf("请输入根的区间：

4、");scanf("%lf",&a);scanf("%lf",&b);if((f(a)*f(b))<0){printf("要求小数点后的位数：");scanf("%d",&e1);while(e1>0){e2=e2/10;e1--;}e2=e2/2;printf("e2=%f",e2);x1=a;printf("第%d次迭代后结果是：%20.19f",i,x1);x2=f(x1);while(fabs(x2-x1)>e2){i++;printf("第%d次迭代后结果是：%20.19f",i,x2);x1=x2;x2

5、=fdao(x1);}printf("共进行%d次迭代过程",i);printf("结果是：%20.19f",x2);}elseprintf("无法进行迭代!");}二分法：迭代法1拉格朗日插值#include#include#includeusingnamespacestd;floatjisuanmokuai(int,float,float[],float[]);voidmain(){floata,x[50],y[50],l;intm,n;cout<<"题目:

6、按下列数据"<>n;cout<<"输入计算次数:"<>m;for(inti=0;i<=m;i++){for(intj=0;j<=n;j++){inth99=i+1,b99=j+1;cout<<"输入第"<

7、的第"<>x[j]>>y[j];}cout<<"输入要计算的x的值:"<>a;l=jisuanmokuai(n,a,x,y);printf("%f",l);}}floatjisuanmokuai(intn,floata,floatx[],floaty[]){floatl=0,w;inti,j;for(i=0;i<=n;i++){w=1;for(j=0;j<=n;j++){if(i!=j)w=w*((a-x[j])/(x[i]-x[j]));}l=

8、l+w*y[i];}returnl;}2牛顿插值#includevoidmain(){doublea,b;cout<<"pleaseinputa=";cin>>a;b=1.044303+0.33825*(a-0.3)+0.3969*(a-0.3)*(a-0.42)-0.1368*