Chapter 13 - Periodic Functions and Trigonometry - 13-1 Exploring Periodic Data - Lesson Check - Page 831: 5

$f(6)=2$ and $ f(11)=2$

Here as the function is periodic, for every $x=1+5k$ and $x=1-5k$ where $k=Z$(Integers) we get $f(x)=2$ Here, as $6$ can be written as $1+5*1$ and $11$ can be written as $1+5*2$ We get $f(6)=2$ and $ f(11)=2$