如何用代数方法求解方程组?

时间:2016-08-12 05:49:37

标签: math wolfram-mathematica

我不确定这是否是正确的地方。这里N,L,H,p和d是参数。我需要解决这个方程组。具体来说,我需要解决b(t)和e(t)。

Variables | t=1    |  t>1  
----------|--------|------------------------  
   n(t)   |  N     |N(1-p)^(t-1)  
   s(t)   |  1     |((1-p+dp)/(1-p))^(t-1) 
   b(t)   |  L     |b(t-1)+p(H-b(t-1))
   e(t)   |(H-L)/2 |e(t-1)+(p(H-b(t-1)))/2
   c(t)   |(1-d)pN |(1-d)pN(1-p+dp)^(t-1)  

请帮助我如何解决这个问题。

2 个答案:

答案 0 :(得分:3)

由于你使用了Wolfram-Mathematica标签,或许你打算使用Mathematica

LAG

返回

select *
from
 (
   select PersonID, Year(taxeDate),PeriodeStartDate ,PeriodeEndDate,
      LAG(PeriodeEndDate) -- previous row's PeriodeEndDate
      OVER (PARTITION BY PersonID
            ORDER BY PeriodeStartDate) as prev_EndDate
   from dbo.Payment 
 ) as dt
where PeriodeStartDate < prev_EndDate

答案 1 :(得分:2)

似乎这些公式给出了循环方程 - 你找到t = 1的值(来自表),然后计算t = 2的值,然后计算t = 3等等

b(t) = b(t-1) + p * (H - b(t-1))
t = 1:   L
t = 2:   b(2) = b(1) + p * (H - b(1)) or 
         L + p * (H - L) = L + p * H - p * L
t = 3:   b(3) = b(2) + p * (H - b(2))

Example: L= 2; p = 3; H = 7;
b(1) = 2
b(2) = 2 + 3 * (7 - 2)  = 17
b(3) = 17 + 3 * (7 - 17) = -13