### Home > CALC > Chapter 3 > Lesson 3.1.2 > Problem3-27

3-27.

If $f(15) =-3$ and $f(20) = 4$, must $f(x)$ have a root between $x = 15$ and $20$? Explain why or why not. Be sure to include sketches that support your reasoning.

Notice the condition of the Intermediate Value Theorem.