All Algebra II Resources
Example Questions
Example Question #2 : Quadratic Inequalities
Solve:
Start by setting the inequality to zero and by solving for .
Now, plot these two points on to a number line.
Notice that these two numbers effectively divide up the number line into three regions:
, , and
Now, choose a number in each of these regions and put it back in the factored inequality to see which cases are true.
For , let
Since this is not less than , the solution to this inequality cannot lie in this region.
For , let .
Since this will make the inequality true, the solution can lie in this region.
Finally, for , let
Since this number is not less than zero, the solution cannot lie in this region.
Thus, the solution to this inequality is
Example Question #1 : Quadratic Inequalities
Solve:
The solution cannot be determined with the information given.
First, set the inequality to zero and solve for .
Now, plot these two numbers on to a number line.
Notice how these numbers divide the number line into three regions:
Now, you will choose a number from each of these regions to test to plug back into the inequality to see if the inequality holds true.
For , let
Since this is not less than zero, the solution to the inequality cannot be found in this region.
For , let
Since this is less than zero, the solution is found in this region.
For , let
Since this is not less than zero, the solution is not found in this region.
Then, the solution for this inequality is
Example Question #2 : Quadratic Inequalities
Solve:
Start by changing the less than sign to an equal sign and solve for .
Now, plot these two numbers on a number line.
Notice how the number line is divided into three regions:
Now, choose a number fromeach of these regions to plug back into the inequality to test if the inequality holds.
For , let
Since this number is not less than zero, the solution cannot be found in this region.
For , let
Since this number is less than zero, the solution can be found in this region.
For let .
Since this number is not less than zero, the solution cannot be found in this region.
Because the solution is only negative in the interval , that must be the solution.
Example Question #7 : Quadratic Inequalities
Solve:
First, set the inequality to zero and solve for .
Now, plot these two numbers on to a number line.
Notice how these numbers divide the number line into three regions:
Now, you will choose a number from each of these regions to test to plug back into the inequality to see if the inequality holds true.
For , let
Since this solution is greater than or equal to , the solution can be found in this region.
For , let
Since this is less than or equal to , the solution cannot be found in this region.
For , let
Since this is greater than or equal to , the solution can be found in this region.
Because the solution can be found in every single region, the answer to this inequality is
Example Question #10 : Quadratic Inequalities
Which value for would satisfy the inequality ?
Not enough information to solve
First, we can factor the quadratic to give us a better understanding of its graph. Factoring gives us: . Now we know that the quadratic has zeros at and . Furthermore this information reveals that the quadratic is positive. Using this information, we can sketch a graph like this:
We can see that the parabola is below the x-axis (in other words, less than ) between these two zeros and .
The only x-value satisfying the inequality is .
The value of would work if the inequality were inclusive, but since it is strictly less than instead of less than or equal to , that value will not work.