👉 In mathematics, a concave function is a function that has a steep negative slope. It can also be defined as a function with a non-negative second derivative, where the first derivative of the function is always less than zero and the second derivative is positive. For example, in calculus, a concave function f(x) is a function whose derivative f'(x) < 0 for all x in its domain. The graph of such a function is often considered to be concave down or inward