is this a function and why y = x2 + 3

1. A motorcycle stunt rider jumped across the Snake River, starting from a bluff overlooking the river and landing on a level with the river. The path of her motorcycle was given approximately by the function H(d) = -0.0003d² +2.19d + 400, where H is measured in feet above the river and d is the horizontal distance from the launch ramp, in feet. a. Sketch and label a picture of the rider's path. b. How high above the river was the launch ramp? c. What was the rider's maximum height above the river, and how far was the rider from the ramp (horizontally) when she reached the maximum height? d. What was the rider's horizontal distance from the ramp when she landed? decimal place, as needed.) (Round answers to one

A rectangular parcel of land has width, w feet. The length of the diagonal, d, between opposite corners is 18 feet more than the length of the parcel. Note that d is lowercase. (a) Express the length, L, of the parcel as a function of d. (b) Express the width, w, of the parcel as a function of d. (c) Express the area, A, of the parcel as a function of d. L = W = A = (d) Suppose a fence is to be built around the perimeter of the rectangular parcel of land. The fencing material will cost $25 per foot. Express the total cost, C, of fencing the parcel as a function of d. C =

What is the zero of the function & what is the x intercept