1. Increasing Function: y = f(x). If h is a very small positive number and f(a + h) >f(a) and f(a)<f(a-h), then at x = a, the function f(x) is called increasing function. That is, if at x = a, the function f(x) is increasing function then f(a) > 0.
2. Decreasing Function: y = fx). If h is a very small positive number and f(a + h) < f(a) and f(a) < f(a-h), then at x = a, the function f(x) is called decreasing function. That is, if at x = a, the function fix) is decreasing function then f(a) < 0.
