What is the inverse of g(x)= 1/x-1 and is it a function? 1/x Yes 1/x +1 Yes 1/x - 1 No 1/y-1 No

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?