Graph of a function
A graph is an illustration method of illustrating the behaviour of a particular function. This is easy to see from a graph how as x changes and the value of the f(x) are changing. Thus the graph is much easier to understand and interpret than a table of values. As an example: by looking at a graph we can tell whereas f(x) is decreasing or increasing as x decreases or increases.
We can tell also whereas the rate of change is slow or fast. Minimum and Maximum values of the function can be seen at a glance. As a particular value of x, it is simple to read the values of f(x) and vice versa that is graphs can be used for estimation reasons. Various functions create different shaped graphs and it is helpful knowing the shapes of some of the much commonly encountered functions. Several types of equations like linear, trigonometric, quadratic, exponential equations can be solved by using graphical methods.