Let . Then…

MATHEMATICS · Single correct · AoPS · Mathematics · Special Functions · Special Functions

Problem

Let

f(x)=\begin{cases}\frac{1}{2}, & \text{if } 0\leq x\leq\frac{1}{2}\\\frac{1}{3}, & \text{if } \frac{1}{2}<x\leq1\end{cases}

. Then

f

is (1) A rational function (2) A trigonometric function (3) A step function (4) An exponential function