We will have the following:
We will be able to tel apart sequences as follows:
Linear sequence: We have that linear sequences follow the form:

Here "x" represents the iteration value for the sequence, "m" the ratio (slope) and "b" a value that modifies the "position" of the sequence. This sequences grows in a linear manner.
Example:

Exponential sequence: We have that exponential sequences follow the form:

Here "a1" is the first term of the sequence, "r" is the ratio and "x" the iteration of the sequence.
We obtain the ratio as follows:

Example:

The ratio for this case:

Quadratic sequence: A quadratic sequence follows the general form