Problem #PRU-64891

Problems Algebra Functional equations Calculus Functions of one variable. Continuity Functions. Continuity (other)

Problem

The numerical function \(f\) is such that for any \(x\) and \(y\) the equality \(f (x + y) = f (x) + f (y) + 80xy\) holds. Find \(f(1)\) if \(f(0.25) = 2\).