Chapter 1 - Section 1.3 - Propositional Equivalences - Exercises - Page 34: 3

$a.$ $\left[\begin{array}{ll} p & q\\ \hline & \\ T & T\\ T & F\\ F & T\\ F & F \end{array}\right.\quad \left.\begin{array}{ll} p\vee q & q\vee p\\ \hline & \\ T & T\\ T & T\\ T & T\\ F & F \end{array}\right]$ $b.$ $\left[\begin{array}{ll} p & q\\ \hline & \\ T & T\\ T & F\\ F & T\\ F & F \end{array}\right.\quad \left.\begin{array}{ll} p\wedge q & q\wedge p\\ \hline & \\ T & T\\ F & F\\ F & F\\ F & F \end{array}\right]$

In the truth tables for (a) and (b): Columns 3 and 4 are identical, so the propositions are equivalent