An even function decreases strictly on (−∞,0). Choose the correct ordering; write a=2^(−7/3), b=3^(−2/7), c=log₃(2/7).

1. Obtain strict size bounds.

   $$0<a<1/4<1/2<b<1,\quad2/7<1/3\implies c<-1$$

2. Order by absolute arguments.

   $$|c|>b>a>0\implies f(c)=f(|c|)>f(b)>f(a)$$

E.

Checks and common pitfalls: A negative argument can have the largest value because f is even.