Challenging Recreational Mathematics: Problem of the Week: 1984 AIME, Problem 12

Δευτέρα 8 Μαΐου 2017

A function $f$ is defined for all real numbers and satisfies $f(2+x)=f(2-x)$ and $f(7+x)=f(7-x)$ for all $x$ .

If $x=0$ is a root for $f(x)=0$ , what is the least number of roots $f(x)=0$ must have in the interval $-1000\leq x \leq 1000$ ?