Question

when a function increase/decrease on interval (a,b) does it also increase/decrease on interval [a,b] if a,b are in domain ?

Answer 1

@ganeshie8 i think is does because of definition

Answer 2

Well a function doesn't increase/decrease at a point, it increases/decreases on an interval. I think it is better to leave the ( ).

Answer 3

i understant that but if you include a,b nothing is bad i thing,, it's more correct

Answer 4

oh i see now,but sometimes you can include

Answer 5

I think you can include if the function is continuous in the closed interval

Answer 6

yeah it's true

Answer 7

you could say
this function is increasing on (1,2] union [2,3)
but that is weird.
when you can just say it is increasing on (1,3)