如何求下函数的最小值

haimingqing

y=(0.8-x*((1+(6.6*x)^(1/2))/(0.97*x*(6.6+(6.6*x)^(1/2))))^(1/3))^2
如何求y取最小值时的x

lin2009

y最小值为0，对应的x ＝1.11601178406975。


对应的详细结果及程序如下：

====== 结果 ======

迭代数: 20
计算用时(时:分:秒:毫秒): 00:00:00:216
计算中止原因: 达到收敛判定标准
优化算法: 标准简面体爬山法 + 通用全局优化法(SM1)
函数表达式: (0.8-x*((1+(6.6*x)^(1/2))/(0.97*x*(6.6+(6.6*x)^(1/2))))^(1/3))^2
目标函数值(最小): 0
x: 1.11601178406975

====== 计算结束 ======
对应的1stopt 程序：
MinFunction (0.8-x*((1+(6.6*x)^(1/2))/(0.97*x*(6.6+(6.6*x)^(1/2))))^(1/3))^2;

qibbxxt

1. >> f = @(x) (0.8-x*((1+(6.6*x)^(1/2))/(0.97*x*(6.6+(6.6*x)^(1/2))))^(1/3))^2
   
2. 
   
3. f =
   
4. 
   
5.     @(x)(0.8-x*((1+(6.6*x)^(1/2))/(0.97*x*(6.6+(6.6*x)^(1/2))))^(1/3))^2
   
6. 
   
7. >> [x,fval] = fminsearch(f,1)
   
8. 
   
9. x =
   
10. 
    
11.     1.1160
    
12. 
    
13. 
    
14. fval =
    
15. 
    
16.   4.1500e-012

复制代码

haimingqing

太强了 谢谢