Question

If the graph of a differentiable function $y=f(x)$ meets the lines $y=-1$ and $y=1$, then the graph

• A. meets the line $y=0$ at least once
• B. meets the line $y=0$ at least twice
• C. meets the line $y=0$ at least thrice
• D. does not meet the line $y=0.$

Answer 1

Answer: (A)

Since the function $y=f(x)$ is differentiable, and meets the line $y=-1$ and $y=1$
$\therefore$ the function is continuous and hence its graph meets the line $y,=0$ at least once.