Answer:

Step-by-step explanation:
A quadratic function is a function in which the highest power of the unknown variable is 2.
Formally, a quadratic function is defined as a function of the form:

From the given options, only B and D has the highest power as 2. Therefore, the equations that represent quadratic functions are:

A line doesn’t have an endpoint
Step-by-step explanation:
log x = 1 + a
a = log x - 1
log y = 1 - a
a = 1 - log y
So
log x - 1 = 1 - log y
log x + log y = 2
log (xy) = 2
xy = 100
Answer:
x = 74
Step-by-step explanation:
We have:
Rπ = 51.4 ⇒ R = 51.4 : π ≈ 51.4 : 3.14 = 5140 : 314 ≈ 16.36 meters