The limit is equivalent to the value of the derivative of

at

. (See definition of derivative)
I think it is not possible to find a certain equation from just a given points, it must have more given information because there is a lot of parabola pass throw (-1,1).
Answer:
D. 
Step-by-step explanation:
Let be
. To find the equivalent expression we must use the following property:
(1)
Based on this fact, we find the following equivalence:

Hence, the correct answer is D.
I think it’s 0.85d, but i’m not sure
Speed = Distance/Time. Let speed be V, distance D and time T
a)Given: D₁ =45km, V₁=x km/h
V₁=D₁/T
V₁=45/T OR T= 45/V₁
b) Given : D₂ =48 km and V₂ = V₁ + 4 km/h
V₂ = 48/T, but V₂ = V₁+4, then:
V₁+4 = 48/T OR T=48/(V₁+4). Since Time is same, then we can write:
45/V₁ =48/(V₁+4), solve for V₁:
45V₁ + 180 = 48V₁
3V₁ =180 and V₁ = x = 60 km/h