Function defined on the set of real numbers by a relationship of the form

*y*=*kx +**b*where*k*and*b*are non-zero real numbers.The graph of a partial variation function does not pass through the origin (0,0) of the Cartesian plane, since

*b*≠ 0.### Example

This is the graph of the function *f* defined by the rule *f*(*x*) = 3*x* − 4.

The rate of change of this function is 3.