GWD 04-35

[小隻]

The operation Δ is defined for all nonzero x and y by x Δ y = x + . If a > o, then 1 Δ (1 Δ a) =
A. a
B. a + 1
C. a/(a+1)
D. (a+2)/(a+1)
E. (2a+1)/(a+1)

ans: E

怎麼解呢? HELP, PLEASE!!

[peche]

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

[小隻]

TKS 'PECHE' FOR CLEAR EXPLANTION.
I GOT IT.

[willy48912005]

想請問一下 "Δ"代表的是什麼意義?

謝謝!