Optimization on Open or Unbounded Intervals - Expii

Finding extrema on open or unbounded intervals is similar to the process for closed intervals. Some additional complications arise, however, because a continuous function might not have any local extrema on non-closed intervals. More importantly, when finding global extrema, you might need to be a little more careful with "boundary" analysis: what happens in the limit as you approach endpoints (for open intervals) or infinity (for unbounded intervals).