Respuesta :

Answer:

7. -

a. 3.5 or 7/2 hours

b. 24.5

c. After 7 hours (and at the beginning when t=0)

8. -

a. 4 seconds

b. 1 second

c. 54 meters

Step-by-step explanation:

7. M(t)=-2t^2+14t

M’(t)=-4t+14

a)

-4t+14=0

4t=14

2t=7

t=7/2

b) M(7/2)=24.5

c)

M(t)=0

-2t^2+14t=0

t^2-7t=0

t(t-7)=0

t=0, 7

8.

a)

h(t)=0

-6t^2+12t+48=0

t^2-2t-8=0

(t-4)(t+2)=0

t=-2, 4

t=4

b)

h(t)=-6t^2+12t+48

h’(t)=-12t+12

h’(t)=0

-12t+12=0

12t=12

t=1

c) h(1)=54

I hope this helps; please vote brainliest!