John M. answered • 03/10/21

Math Teacher/Tutor/Engineer - Your Home, Library, MainStreet or Online

f(x)=240x−16x^{2}

(A) The instantaneous velocity function v=f′(x)

f'(x)' = v = 240 - 32x x = 7.5 seconds

(B) The velocity when x=0 and x=2 sec

When x=0, v = 240 ft/sec

When x=2

v = 240 - 32(2) = 64 feet/sec

(C) The time(s) when v=0

0 = 240x−16x^{2}

16x^{2 = } 240x 16x= 240

x = 0, 15 sec