Focus and Connections: Functions, Domains and Ranges, Viewing and Interpreting Graphs, Even and Odd functions symmetry, Functions defined in pieces, Absolute value functions, Composite Functions, Interval Notations
Functions f(x): A way to show a connection between two values and several sets of two values. Several sets of values together is seen as a function. Functions are not only in math, but everywhere in life. Some examples of functions are, one to one functions, quadratic functions, linear functions, many to one functions, and polynomial functions.
Domain and Range: The domain is a restriction of where all possible x values of a function can be applicable. The range is a restriction of where all possible y values of a function can be applicable.
Viewing and Interpreting Graphs: A vertical line test can be used to determine whether a function exists or not on a graph. This is to check if any x values on the graph repeat. If this happens, there is no function.
Even and Odd functions symmetry: A f(x) function is even if f(-x)=f(x) ∀xeD. This is symmetrical from the y-axis (x=0). A f(x) function is odd if f(-x)=-f(x) ∀xeD. This is symmetrical from 0,0 (the origin). Replace x with -x and simply simplify the equation, and if it comes out to be f(-x) = f(x), it is an even function. However. if it comes out to be f(-x) = -f(x), it is odd. 
Piecewise Functions: A function made from several different pieces of different functions and equations. Each part of the function will have a separate domain as well.
Absolute Value Functions: These are functions where there cannot be any negative x or y values. Any negative value is changed to its positive value. For example, a value of x=-3 has an absolute value of x=3. The equation for an absolute value is written like | x |.
Composite Functions: When two functions are present and a small part of the range of the first function is included in the range of the second function. Therefore, this is when a function is written inside another function. When you have f(x) and g(x), and f [g (x)] is the composite function, you would substitute the g(x) value into f(x).
Interval Notations: This is used to show all applicable values between two endpoints. It is a way to represent domain and range of a function. If a value can be represented in a specific part of a function, a closed circle is used and a closed bracket is used. If a value cannot be represented in a specific part of a function, an open circle is used and an open bracket is used. Closed brackets = [x,y]
Open brackets = (x,y)