Katherine+&+Amanda+(Dickson)

Katherine Blakely's Real Life Parabola Direction of opening: down Line of Symmetry: x=-0.1 Domain: {XER|-1.8 ≤ x ≤ 1,7} Range: {YER|0.6 ≤ y ≤ -0.4} Estimated Vertex: (-0.1, 0.6)

A fun fact about this bridge, is that it is the earliest known fully-stone open-spandrel segmented arch bridge, called the Zhaozhou Bridge, in southern Hebei province in China. It is 37.5m long, and was apparently completed in the year 605 by the Sui Dynasty engineer Li Chun. It is relatively lightweight due to the four semi-circular arch spandrels which allow additional flood waters to pass through.

My estimated parabola was very close to my calculated parabola; I assume what made the difference was that I rounded the decimal spaces.

[[image:amandacurrysparabola.PNG width="800" height="392"]]
The Parabola of best fit: **__ Properties: __** -**Vertex** (0,3) -**Direction of opening:** down -**Domain: {XER l -3 < X < 3** -**Range:** **-Axis of Symmetry:** 0

My estimated parabola was in decent proximity to the one Autograph calculated. I could have estimated my points on the graph better, to me more consistent. It was difficult because a slinky is coil-shaped. I could have estimated my vertex more accurately. To be honest, I made my numbers whole numbers so that it would avoid big numbers when doing my math. I wrote that my vertex was (0,3), however it was actually (0, 3.3) and the point on my graph I said was (3,0) which was actually around (2.7, 0).
 * This image is of a Slinky. Over the years over 250 million have been sold! This toy was invented in 1945 by American naval engineer, Richard James who was inspired when a spring came loose on a ship and fell to the floor in front of him.