Topics:
• More on inequalities and intervals: inequalities which contain a $\neq$ sign. (Not in the textbook – see the notes below.)
• Functions and function notation (Session 2, section 2.2)
• Domain and range of a function (Session 2, section 2.2)
• Functions which are defined by tables of values (Session 2, section 2.2)
Inequalities which contain a $\neq$ sign:
Example: $x \neq 3$. The graph of this inequality contains all the points on the Real number line except for 3, in other words there is an open circle on 3 and everything else is shaded.
In interval form, $x \neq 3$ can be written as $(-\infty, 3)\cup (3, infty)$.
In general, when an inequality contains at least one part with a $\neq$ sign, you have to omit that number from the graph (by putting an open circle on it).
