Which describes the range of the parent absolute value function?
a.{y | y is a real number}
b.{y | y is an integer}
c.{y|y > 0}
d.{y|y < 0}

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?