1.7 Linear and Absolute Value Inequalities Flashcards
a statement that two algebraic expressions are not equal in a particular way
inequality
symbols for inequalities
the set of all real numbers for which the inequality is true
solution set to an inequality
4 different ways to express an inequality as a solution
1) graphically - number line with (), [ ]
2) inequality notation
3) interval notation
4) set-builder notation
What is set-builder notation?
{variable | mathematical statement involving the variable. }
What does “|” mean in mathematics?
“such that”
intervals that use the infinity symbol
unbounded intervals
the endpoint is not included in the interval and parenthesis used
open endpoint
the endpoint is included in the interval - brackets used
closed endpoint
a sentence containing two simple inequalities connected with the words “and” or “or”.
compound inequality
an interval contains both of its endpoints
closed interval
an inequality that does not involve infinity
bounded
symbol for intersection
symbol for union
symbol for “is a member of”
symbol for “is not a member of”
In absolute value inequality problems, what must you remember?
1) Treat it just like an absolute value equation. Isolate the absolute value first. If you divide or multiply by a negative number in the isolation process, you must switch the direction of the inequality symbol.
2) Determine if the statement is an “and” or an “or”
3) Solve the inequalities.
4) Graph the solutions.
5) Make a decision about the final answer and write the answer in interval notation.
When you multiply or divide by a negative number in an inequality statement, what must you remember?
switch the direction of the inequality symbol
After isolating the absolute value, what type of problem do you have with a
“or” statement or union of two inequalities
After isolating the absolute value, what type of problem do you have with a
“and” statement or the intersection of two inequalities
what does “or” stand for with inequalities
union
what does union mean?
putting answers together to make a combined statement that make an inequality true.
what does intersection mean?
where the answers to inequalities overlap
what does “and” stand for with inequalities
intersection
when an endpoint is “included” as part of an answer in an interval, what symbol is used in interval notation?
brackets [ or ]
when an endpoint is “not included” as part of an answer in an interval what symbol is used in interval notation?
parenthesis ( or )
What symbol is used in interval notation for the infinities
parenthesis ( or )
In algebra II, we used open circles on graphs. What have they been replaced with in College Algebra?
parenthesis ( or )
In algebra II, we used closed circles on graph. What have they been replaced with in College Algebra?
brackets [ or ]
If an inequality has an absolute value in the problem around the variable, how many inequalities must you set up?
2
if an inequality does not have an absolute value in the problem around the variable, how many inequalities must you set up?
only 1
When do you determine if the problem is an “and” or an “or” statement?
after isolation of the absolute value.