Richard shot a homemade rocket from a field behind is house. The height of the rocket, in feet, t seconds after it left the ground is shown in the function below.
r(t) = -30t + 390t
What is the domain of the height function?
A. (-infinity sign, infinity sign)
B. (0,13)
C. (0, infinity sign)
D. (13, infinity sign)
I believe the answer is B. Can you please doublecheck and tell me if I am wrong???
surely something parabolic like
r(t) = -30 t^2 - 390 t
and that is also really nonsense on this planet
where
h = Vi t - 4.9 t^2 in metric units
or
h = Vi t - 16 t^2 in feet etc
but anyway
well, when t = 0 it starts
we hit he ground again when
30 t^2 = 390 t
or
t = 13 seconds or whatever your time unit is on this planet
so the above ground domain is from
t = 0 to t = 13
so I agree, B
To determine the domain of the height function, we need to consider the values of t that are valid inputs for the function. In this case, t represents time in seconds after the rocket left the ground.
The height function, r(t) = -30t + 390t, is a polynomial function. Polynomial functions are defined for all real numbers, which means that there are no restrictions on the domain of this function. Therefore, the correct answer is A. (-∞, ∞).
So, you are incorrect. The correct answer is not B, but A.