穿過原點,c
=0;
y
=
2x?
[加在以-u結尾的法語詞源的名詞之後構成復數]
點(n,Sn)在f(x)上,
錫
=2n?
-
n;
S(n-1)
=2(n-1)?
-(n-1);
標準語
-S(n-1)
=
2(2n-1)
-1
=4n
-3 = a(n);
a1
=4*1
-3
=1;
(2)b(n)
=
2/(4n-3)(4n+1)
=(1/2)((1/(4n-3))
-
(1/(4n+1));
T[n]=
1/2(1/1
-1/5
+1/5
-1/9
+...
+
-(1/(4n+1)))
=
1/2
(1
-
(1/(4n+1))
=
2n/(4n+1)
2n
m
______
& lt______
4n
+1
2008
因為2n/(4n+1)
=1/2
-(1/2)/(1+4n)& lt;1/2,
並且是遞增的函數,
m/2008
& gt=
1/2是
妳可以拉,
m
& gt=1004
m
=1004是最小的整數。