Can a Straight Line Have Absolute Maximum Minimum

Steps to find increasing and decreasing interval of any function, f(x), are:
find the first derivative, f'(x)
find critical numbers, f'(x) = 0 or does not exist (DNE)
INTERVAL TABLE TEST:
These critical numbers divide the domain in intervals. Test each interval with a test point.
RESULT:
If f'(x) is greater than 0 then f(x) is increasing.
If f'(x) is less than 0 then f(x) is decreasing.
#calculus #derivativeapplication #increasinginterval #decreasinginterval #mcv4u #anilkumar #globalmathinstitute #absolutemaximum #absoluteminimum

[seven]

How would you express absolute minimum or maximum in open intervals? For example, say I have a function f(x)=2x, and I want to know the maximum and minimum in the closed interval [0, 2]. It's pretty obvious that the answer here is that 0 is the minimim and 2 the maximum. But what if instead of [0.2] we had (0.2)? Would the maximum be a limit? What about the minimum?

[cowgirlable]

Can you have a max or min in a closed interval of a horizontal line?

[iamnobody]

If it's an interval, then the values are not absolute anymore, are they?