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1、黄金分割法思想黄金分割法是建立在区间消去法原理基础上的试探方法，即在搜索区间a,b内适当插入两 点a 122,并计算其函数值。al, a2将区间分成三段。应用函数的单谷性质，通过函数值人 小的比较，删去其中一段，使搜索区间得以缩短。然后再在保留卞来的区间上做同样的处置 如此迭代下去使搜索区间无限缩小，从而得到极小点的数值近似解。2：程序框图C语言程序#include#iiiclude#define p 0.618 double f(double x)double y;v=x*x+2*x;J7retuin(y)；iiit main()double double x);int m=0;double
2、 a,b,a 1 ,a2,a3,c=0001;double yl,y2;a=-3;b=5;al=b-p*(b-a);a2=a+p*(b-a);yl=f(al);y2=f(a2);pnntf(Ma=%.31f a 1 =%31f a2=%.31f b=%31fm= 1 ,a2,b); printf(,yl=%.31f y2=%31fW；f(al)卫a2);doif(yl=v2)a=al;al=a2;yl=y2;a2=a+p*(b-a); y2=f(a2);elseb=a2;a2=al;y2=yl;al=b-p*(b-a); yl=f(al);printf(Ha=%31f a 1 =%31f a2
3、=%31f b=%31fiT ：a,a 1 ,a2,b);pnntffy2=%31f yl=%31fE,y 1 ,y2); m+; while(fabs(b-a)/b)=c|fabs(y2-vl)/y2)=c);a3=(a+b)/2;pnntf(”函数极小值点 a3=%.51fm”,a3); printff1 函数值 y=%.51fji,f(a);pmitf(”迭代次数 k=%dn”,m);return 0:结果ra 够 453863563 classes3S63663.CPP*includelc *C:I)ocuji8nt8 and SettinesAdaini8ttatOKJK对 4664
4、63664Dsffinclude tdrFinr p 0.618 double f;yi-f(ai);y2-f(a2);prlntf(-a-%.31f a1-%.3lf a2-.31f printfC*9l=t.31F y2=t.31fn-,F(a1 doyl=0.115y2=7.667aal1.111 a2-fl.056 b-1.944 y2=-9.988 yl=6.11Sa3.TO0 al1.833 o21.111 b-W.056y2 =-0.367 yl =-.988a1.833 ol1.111 020.665 b-W.056JF20.988 yle.88fia1.833 dT38? 1
5、21.111 b0.66520.850 yl0-98fisi =-1.38?=-1.111 a2=-9.941 b=-0.66Sy20.986 yl- B.9?7si =-1.111 1 =-0.941 a2 =-0.836 b=-0.66Sy2W.997 yl9.?731.111 all.Hftb a2-0.941 b-0.36 /2-1.WU yl-0.9971.111 al1.04G a2l.RRG b0.941 y2=-0T98 yl =-l 。啊1.0-16 al1.ARG a20.981 b0.941 kf2 =-1.000 yl =-1.090“-146 al1.021 o21.
6、006 b-0.9811.021 al1.0U6 020.997 b0.981吆1.D时 yl-l .ROAd-B997 120.991 b09Bl 21.AflO yll .ROAsi=-l.e06 al =-1.000 a2=-0.997 b=-0.991 y21.000 yl1.000si=-l.e06 al =-1.002 a2 =-1.009 b=-0997 y2-l.WU yl-l.Ua01.802a2-0.999 b-0.99?/2-1.WU yl-l.Ua0*-1.002 al1.0R1 a2l.ARfl b0.999a-al：rChiw&V 目幵 IcView JIP I38
7、6363.exe 0 error(s)t 0 warning(s)I小纽建ZW； 在文件1中戦左文件2中皱绪果沁 臥呢4y2=-l 列B yl =-ll.Ml al1.APR a2l.ARfl b0.999 y2=-1.000 yl=-1.090al.eei O1-1.001 a2-l.0W b-l.0W y2=-i.WH1 yl =-l.Meal.eei ai-i.0uu a2-i.uw b-i.ua21.Ann 01. roa殆救薇小值H31 吩M2迭代庚数炸19Progs uiy key to continue 4564535644S3EBS63 - FIjctU)&cuaaats a.哲Vicroxoft R；-I
