We will graph the given quadratic inequality then we will find the error Stella-Jon spotted in Ron-Jon's solution. To graph the quadratic inequality, we will follow three steps.
Let's draw the graph of the related function, which is If you need explanations on graphing parabolas, please refer to this exercise.
Since produced a false statement we will shade the region that does not contain the point. Also, note that the inequality is not strict. Therefore, the parabola will be solid.
Now, let's compare the correct graph with the given one.
We can see that the mistake Ron-Jon made was that he shaded the wrong region. By the way, you guessed right. Madame Christina is actually Ron-Jon's surprisingly sneaky math teacher.