Hello Kaushik,
When finding intervals for increasing and decreasing,
we usually find strictly increasing and strictly decreasing.
And in strictly increasing or decreasing, we use f'(x) > 0
Thus, the interval will have open bracket. (Since there is greater than sign).
Please ask us the questions in which you have a doubt, I will be happy to help.
Written on May 15, 2017, 10:53 a.m.