Linear functions are those whose graph is a straight line. A linear function has the following form. y = f(x) = a + bx. A linear function has one independent variable and one dependent variable. The independent variable is x and the dependent variable is y.
Linear Functions
www.columbia.edu/itc/sipa/math/linear.html
A FUNCTION of x can be just about anything which plots one value of y for each x
a sine wave a parabola etc
as I mentioned, note this:
If you can draw a vertical line on the same coordinate plane as your graph such that the vertical line intersects your graph in more than one point, the equation is not a function--it is called a relation. Example: the graph of the circle x2 + y2=9 is a relation.
