類題
0=12+9=21
a at ar
設a,b,c為相異的三數,若a,b,c成等比數列,且a+b,b+c,c+a成等差數列,試求
之值。容:
a+b
b+c
d
b=ar, c=ar" (a =o)
=a+b, btu, cta #I
1/2 = (b + c) = (a+b) + (c+a) pp ²a =b+U
學習概念2
b
b
U
b
67/200
9
q
2
Phth 2a=artar =)) +r-2-0
rourorl
bet & -zaa - Yana =
b+c=-=-za+ya+2²=2a
a+bat
atb) = ((+a)-(b+c)
=&#a-6-*
數列的規則 —— 遞迴關係
2
b=2a-l
(2a-2)=1]
=) 40-41² + 1² =