Answer:
(A)
N(T(t)) = 416t² - 242.4 - 135.16
(B)
Time = 27.30 hours
Step-by-step explanation:
Given
N(T) = 26T² - 123T + 25
T(t) = 4t + 1.2
Solving for the composite function.
Substitute T for 4t + 1.2 in N(T)
N(T(t)) = 26(4t + 1.2)² - 123(4t + 1.2) + 25
N(T(t)) = 26(4t+1.2)(4t + 1.2) - 123(4t + 1.2) + 25
N(T(t)) = 26(16t² + 9.6t + 1.44) - 492t - 147.6 + 25
N(T(t)) = 416t² + 249.6t + 37.44 - 492t - 172.6
N(T(t)) = 416t² + 249.6t - 492t + 37.44 - 172.6
N(T(t)) = 416t² - 242.4 - 135.16
Solving for time.
We have that
N(T) = 16044
N(T) = 26T² - 123T + 25
This gives
16044 = 26T² - 123T + 25
26T² - 123T + 25 - 16044 = 0
26T² - 123T - 16019 = 0
Solve by quadratic, we have.
T = 27.299506396472
Or
T = -22.568737165703
Since time can't be negative
T = 27.299506396472
T = 27.30 (approximately)