2. It is a function which is defined by multiple sub-functions, and sub-function applying to a certain interval of the main function's domain
3. To tell if a function is continuous or non-continuous is by the boundary points
4. For all values of x less than zero, the first function (−x) is used, which negates the sign of the input value, making negative numbers positive and for all values of x greater than or equal to zero, the second function (x) is used, which evaluates trivially to the input value itself.
5. Quadratics
6. In the form of f(x) = ax^2 + bx + c and a, b, and c are not equal to 0.
7. The graph is called a parabola, they can open up or down and can vary in width and steepness but they all have the basic "U" shape.
8. Any function can be written in standard form by completing the square.
