idk why i got the last question wrong

[sterile veldt]

Why not [0, +∞)?

[versed totem]

What makes you think you got it right?

[dusty ridge]

Why isn't the function continuous?
If the domain is really meant to be [0, ∞), then it's continuous

[sterile veldt]

I think the mistake is that ||Melon wrote (0, +∞) for the domain instead of [0, +∞).||

[dusty ridge]

I'm asking about question a

[sterile veldt]

Oh.
Well, that asks about all possible values of t. So, ℝ.

[dusty ridge]

If that's true, the question is badly worded

[sterile veldt]

Yeah, it is a bit odd.

[honest hare]

My answer for this: domain = [0, +∞), since t can be 0. The only value where the function is undefined is at t = -4.5. The value is outside the relevancy of the required domain. Hence, [0, +∞).

[sterile veldt]

But if t can't be 0, why did you include it in the domain?

[slim shell]

t can definitely be zero, I think you meant that the denominator can't be zero.

[sterile veldt]

Oh, yeah, that's probably what they meant.

[honest hare]

I apologise, mistakenly put can't instead of can.

Edited the message, thanks.

[sterile veldt]

Ah, ok, no problem!

[honest hare]

Is my thinking about the problem correct? I didn't touch anything about limits for an year or so.

[sterile veldt]

Well, yeah. Though, limits aren't really needed here.
The natural domain for something that's defined as time to do a task would be [0, +∞), with the constraints imposed by the expression of the function.
So, since M(t) is defined everywhere on that ray, the domain stays like that.