The graph of $y=f(x)$ is shown above. If $-2\leq x\leq 6$, for how many values of $x$ does $f(x)=1$?

เฉลยละเอียด

[STEP]Draw the horizontal line $y=1$ and then count the intersection points[/STEP]

Count the intersection points of $x$ such that $-2\leq x\leq 6$. It is easy to see that there are $3$ points so the answer is three.

[ANS]There are three of them[/ANS]