ISI2015-DCG-57

Question

Let $y=\lfloor x \rfloor$, where $\lfloor x \rfloor$ is greatest integer less than or equal to $x$. Then

• A. $y$ is continuous and many-one
• B. $y$ is not differentiable and many-one
• C. $y$ is not differentiable
• D. $y$ is differentiable and many-one

Answer 1

The graph is discontinuos, so non-differentialble, and for two real numbers, a common image is there…

so Option B