Christian is rewriting an expression of the form y= ax + bx + c in the form y = a(x - h)2 + k. Which of the following must be
true?
Oh and k cannot both equal zero
Ok and chave the same value
the value of a remains the same
O h is equal to one half-b

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?