由 peche » 2005-11-09 17:00
The operation Δ is defined for all nonzero x and y by x Δ y = x + x/y If a > o, then 1 Δ (1 Δ a) =
E 2a+1/a+1
--> 1) (1 Δ a) = 1+1/a
--> 2) 1 Δ (1 Δ a) = 1 Δ (1+1/a) = 1+ [1/(1+1/a)]
= 1+ [1/(a+1/a)] = 1+ (a/a+1) = (a+1+a)/(a+1)
= ans E