*Graph of logarithmic function

The function y = log_b x is called a logarithmic function, it is not defined for x ≤ 0.

It is a decreasing function for 0 < b & increasing for b > 1.  The y – axis is an asymptote of the curve

y = log_b x. The x intercept is the point (1, 0).

*Shape of y versus x graph

Let a physical quantity y depends on other physical quantity x, this dependence is called a mathematical function & usually expressed as

y = f (x) (read as y is a function of x).

The dependence of y on x can be visualised by drawing a graph of function y = f (x). While plotting graphs the independent varaible is taken on horizontal line & dependent on vertical line. Shape of y versus x graph depends on the type of function.

Following types of y versus x graphs are frequently encountered in Physics.