This document discusses mathematical limits and their theorems. It defines a limit as the value a function approaches as the input tends toward a point without reaching it. Examples are provided to illustrate limits. Ten theorems of limits are then outlined: (1) the limit of a constant function is the constant, (2) the limit of x as x approaches a is a, (3) the limit of a linear function is the function evaluated at the point, (4) the limit of a square root function is the square root of the point, (5) the limit of a sum is the sum of the limits, (6) the limit of a product is the product of the limits, (7) the limit of a