The graph of logarithmic function y = log_a x depend on the base a. For a * 1 logarithmic function is strictly increasing. Examples: y = log_2 x, y = log_5 x, y = log_(square root of 2) x. For 0 * a * 1 logarithmic function is strictly decreasing. Examples: y = log_0.3 x, y = log_1/2 x, y = log_2/3 x. Properties logarithmic function: Domain: D = (0,∞). Image: ZW = R. Zeros: x = 1. A graph of any logarithmic function contains point (1,0) on x-axis. The logarithmic function is injective.