Quadratic Inequality
Method
Method
There are 4 steps needed to solve a quadratic inequality.
There are 4 steps needed to solve a quadratic inequality.
Step 1: Ensure that one side of the inequality is zero. (Eg. x² − 3x − 4 > 0)
Step 1: Ensure that one side of the inequality is zero. (Eg. x² − 3x − 4 > 0)
Step 2: Factorise the quadratic function. (Eg. (x − 4)(x + 1) > 0)
Step 2: Factorise the quadratic function. (Eg. (x − 4)(x + 1) > 0)
Step 3: Make a quick sketch of the quadratic function and shade the correct region. See diagram below.
Step 3: Make a quick sketch of the quadratic function and shade the correct region. See diagram below.
Try it!
Try it!
Use the applet below to check your understanding of quadratic inequalities.
Use the applet below to check your understanding of quadratic inequalities.