Chapter 1 - Section 1.4 - Properties of Real Numbers and Algebraic Expressions - Exercise Set - Page 39: 32

-1, 1

We are given that a number $a=1$. We know that the opposite of a number $a$ is $-a$, so the opposite of $a=1$ will be $-a=-1$. We know that the reciprocal of a nonzero number $a$ is the number $\frac{1}{a}$, where $a\times\frac{1}{a}=1$ Therefore, $\frac{1}{a}=1$, as $1\times1=1$. In other words, the reciprocal of 1 is also 1.