Answer:
[2.1, 3]
Explanation:
Given the height of the ball modelled by the equation;
h(t) =-4.9t^2+25t+6
Required
Domain for 36.9m
To get that we are to find the value of the input variable which is the time t when h(t) = 36.9
Substitute
36.9 = -4.9t^2+25t+6
multiply through by -10
-369 = 49t²-250t-60
49t²-250t-60 + 369 = 0
49t²-250t+309 = 0
Find the domain of t
49t²-147t-103t+309 = 0
49t(t-3)-103(t-3) = 0
(49t-103)(t-3) = 0
49t - 103 = 0 and t-3 = 0
49t = 103 and t = 3
t = 103/49 and t = 3
t = 2.1 and t = 3
Hence the reasonable domain for 36.9m is [2.1, 3]