A function f(x) is said to be a decreasing function on (a, b) , if x1 < x2 => f(x1) > f(x2) for all x1, x2 Є (a, b). Thus, f(x) is strictly decreasing on (a,b) if the values of f(x) decrease with the increase in the values of x. File:Integral apl obsah2.svg This calculus-related article contains minimal information concerning its topic. You can help the Mathematics Wikia by adding to it.