Section 1.1

Question 1

Function

Answer 1

A function f is a rule that assigns to each element x in a set D exactly one element, called f(x), in a set E.

Question 2

The Vertical Line Test

Answer 2

A curve in the xy-plane is the graph of a function of x if and only if no vertical line intersects the curve more than once.

Question 3

Absolute Value

Answer 3

|a| = a if a is greater than or equal to 0
|a| = -a if a is less than 0

Question 4

Increasing Function

Answer 4

A function f is called increasing on an interval I if f(x1)

Question 5

Decreasing Function

Answer 5

A function f is called decreasing on an interval I if f(x1)>f(x2) whenever x1