## Calculus 10th Edition

As $x$ tends to zero, the value the limit takes differs depending on which side you are approaching zero from. If you are approaching $0$ from the left, you get the limit to equal $-1.$ If you are approaching $0$ from the right, you get $+1.$ These kind of problems will be given specific terminology and will be studied thoroughly in the next section. This specific question was also dealt with in Sec $1.2$ Example $3.$