Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$-1$
The given expression, $-1$ is equivalent to $\dfrac{-1}{1}$. To find its reciprocal, interchange the numerator and the denominator. Hence, the reciprocal is \begin{array}{l} \dfrac{1}{-1} \\\\= -\dfrac{1}{1} \\\\= -1 .\end{array}