Limits Of Polynomials and Rational Functions:

If P(x) and Q(x) are polynomials, then:

lim_x®a P(x) = P(a)

and

Limits can be approached from the negative ( or left ) or the positive ( or right ) side of a number denoted as:

lim_x®a- f(x) = b or lim_x®a+ f(x) = b

If lim_x®a- f(x) ¹ lim_x®a+ f(x) , then

lim_x®a f(x) does not exist

If lim_x®a- f(x) = lim_x®a+ f(x) = b , then

lim_x®a f(x) = b