If you graph a linear function, you get a line. If you graph a quadratic function, you get something called a parabola. A parabola tends to look like a smile or a frown, depending on the function. Check out this tutorial and learn about parabolas!
Orange Door Meanings. Orange is a colour associated with Mercury, which is the swiftest of the planets. Indeed the planet as the fleet-footed Roman god is symbolic of for reception, communication, perception, commerce, movement, intelligence and flexibility. With these kind of qualities, it might be a good idea to paint your business door orange.
In China, it's tradition to paint the front door red before the new year, to invite good luck and happiness. In Catholocism, the red door on a chapel symbolized the blood of christ, and other martyrs, to signify that the ground beyond the door (inside the church) was holy, and a sanctuary from physical and spiritual evils.