Limits of fuctions as x approaches a constant

When a function *f* is defined by some expression on some reduced neighborhood of a real number *a*, if we substitute *a* into this expression and it makes sense, then the outcome is the limit of *f* at *a*.

Look at the sample:

But, as you compute limits of functions as x approaches a constant, you can find several possible solutions:

- The limit is equal to a constant
- The limit is plus or minus infinity
- The limit does not exit

Try to compute the following limits: