Interpret the equation *y *= *mx *+ *b *as defining a linear function, whose graph is

a straight line; give examples of functions that are not linear. *For example, the function A = s2 giving the area of a square as a function of its side length is not linear because its graph contains the points (1,1), (2,4) and (3,9), which are not on a straight line.*

**8.F Functions**

**8.F.A** *Define, evaluate, and compare functions.*