There are two types of easy limit problems: the ones you should just memorize and the ones where you can plug in the *x*-number and get the answer in one step.

## Limits to memorize

You should memorize the following limits to avoid wasting time trying to figure them out. (Pay special attention to the last three limits.)

(*y* = *c* is a horizontal line, so the limit — which is the function height — must equal *c**,* regardless of the *x*-number.)

## Plugging and chugging

You can use the plug-and-chug method to solve some limit problems. Just plug the *x*-number into the limit function, and if the computation results in a number, that’s your answer (don’t forget that zero divided by anything other than zero equals zero which is, of course, a number). For example

This method always works for limits that involve continuous functions and functions that are continuous over their entire domains. These are well-duh limit problems, and, to be perfectly frank, there is really no point to them. The limit is simply the function value.

The plug-and-chug method also works for any other type of function, including piecewise functions, unless there is a discontinuity at the *x*-number you plug in. (A piecewise function has separate pieces, where each part of the piecewise function has its own equation.)