Question

Question #ac14c

Answer 1

I think I understand your question. Please see below.

Explanation:

`[1,5[` = the set of all `x` with `1 <= x < 5`.
Another notation is `[1,5)`

`[2,3] = {x|2 <= x <= 3}`

`]4,9] = {x|4 < x <= 3c}`
Another notation is `(4,9]`

Answer 2

See below

Explanation:

It means that the interval of a graph (also known as an domain of an graph)

`[0, pi/2]`

graph{sin(x) [-10, 10, -5, 5]}

which means the domain of the interval of `sin(0)` to `sin(pi/2)`

its also really important if you want to find the area under a function like `f(x) = e^x`

graph{e^x [-10, 10, -5, 5]}

say i wanted to find the area under the curve from the interval `[0, 1]`

you need to find it using an definite integral `int_0^1 e^xdx`

which would be `e^0+e^1`

`= e - 1`

`= 1.73`