Answer:
c
Step-by-step explanation:
Answer:
Amy is (21.6 - 14.4) 7.2 km/hr faster than Bill.
Distance = speed / time
Amy's speed
40 minutes = 40/60 = 2/3 hours
14.4 = speed / 2/3
Speed = 14.4 * 3/2 = 21.6 km/ hr
Bill speed
60 minutes = 1 hour
Speed = 14.4 km / hr.
I find it best to switch everything exponents when taking derivatives.
F(x) = 7/x
Same as..
F(x) = 7x^-1
Take derivative..
F'(x) = -7x^-2
Plug in x = 1
F'(1) = -7(1)^-2
F'(1) = -7