The dynamic programming recursion (minimization) can be written ...

[mrsjacobs44]

The dynamic programming recursion (minimization) can be written
  a.f_t(i)=min(cost during stage t) - f_t+1(new state at stage t+1).
  b.f_t(i)=min(cost during stage t) + f_t+1(new state at stage t+1).
  c.f_t+1(i)=min(cost during stage t+1) + f_t(new state at stage t).
  d.f_t-1(i)=min(cost during stage t-1) + f_t+1(new state at stage t+1).

Question 2

Equipment replacement problems
  a.determine how often equipment should be repaired.
  b.determine how a machine should be recycled.
  c.determine how a machine should be repaired.
  d.determine how long a machine should be utilized before it is traded for a new one.

[jointhecircus]

Answer to Question 1

correct: b

Answer to Question 2

correct: d

[mrsjacobs44]

Both answers were spot on, thank you once again

[jointhecircus]

Great! Please up vote