Discrete Math - equivalence laws

[Waggattack]

I need to show that P<->Q is logically equivalent to ( P ^ Q ) v ( ~P ^ ~Q)

So far I have P <-> Q is equivalent to ( ~P v Q ) ^ ( ~Q v P ) by a example

I have no idea where to go from here

 

[tiny-tim]

Hi Waggattack!

( ~P v Q ) ^ ( ~Q v P )

Now use the distributive law (ie, expand).

 

[HallsofIvy]

Wouldn't a fairly simple "truth table" suffice?