Inequalities

Question 1

One rule for solving inequalities

Answer 1

Multiplying or dividing and inequality by a negative number of changes the direction of the inequality sign

Question 2

Set notation

Answer 2

Use curly brackets write like this :

{x:x<5} set of values of x such that….

Question 3

Empty set

Answer 3

O with bar in the middle

Means set contains nothing

Question 4

Union

Answer 4

U

The union of two sets is everything contained in either set

Question 5

Intersection

Answer 5

n of two sets is only the things present in both sets

Question 6

What can you use brackets for?

Answer 6

Show an interval

( value not included

[ value included

(3, 5] means 3

Question 7

Solving quadratic inequality

Answer 7

Sketch a graph

Never divide by x as could be negative number

Find where curve crosses x axis by setting y=0

Use sketch to see where inequality is true

Question 8

Finding a region that satisfies the inequalities given…

Answer 8

Sketch the curves or lines and test the coordinates of a point (origin) in each inequalities.

The region you’re after include the areas where each inequality holds true for any tested point.

Question 9

Sketching lines

Answer 9

=< sketch with solid line