increasing decreasing functions

[rustic scarab]

while ascertaining intervals for which the function is increasing/decreasing where can we use and not use closed intervals?

[honest sentinel]

increasing means f'(x) > 0, the sign is "greater than" not "greater than or equal to", therefore we use open interval for the upper bound, same for the case of decreasing

[rustic scarab]

ohhh

so we always omit critical points when mentioning increasing/decreasng intervals?

[honest sentinel]

yes

[rustic scarab]

got it thankss