## College Algebra (6th Edition)

A function is increasing if for any $x_1\lt x_2$, $f(x_1)\leq f(x_2)$. A function is decreasing if for any $x_1\lt x_2$, $f(x_1)\geq f(x_2)$. A function is constant if for any $x_1\lt x_2$, $f(x_1)= f(x_2)$.