Which exponential function grows the fastest? a) f(x) = 5·2x b) f(x) = 4·3x c) f(x) = 3·4x d) f(x) = 2·5x

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?