解答 - 几何数列

要找到系列的通用形式，将第一项：$$a=1,965$$ 和公比：$$r=0.9923664122137404$$ 插入几何级数的公式：

$$a_1=1965$$

$$a_2=a_1·r^{n-1}=1965\cdot {0.9923664122137404}^{2-1}=1965\cdot {0.9923664122137404}^1=1965\cdot 0.9923664122137404=1950$$

$$a_3=a_1·r^{n-1}=1965\cdot {0.9923664122137404}^{3-1}=1965\cdot {0.9923664122137404}^2=1965\cdot 0.9847910960899714=1935.1145038167938$$

$$a_4=a_1·r^{n-1}=1965\cdot {0.9923664122137404}^{4-1}=1965\cdot {0.9923664122137404}^3=1965\cdot 0.9772736068068418=1920.3426373754442$$

$$a_5=a_1·r^{n-1}=1965\cdot {0.9923664122137404}^{5-1}=1965\cdot {0.9923664122137404}^4=1965\cdot 0.9698135029380873=1905.6835332733415$$

$$a_6=a_1·r^{n-1}=1965\cdot {0.9923664122137404}^{6-1}=1965\cdot {0.9923664122137404}^5=1965\cdot 0.9624103464271095=1891.1363307292702$$

$$a_7=a_1·r^{n-1}=1965\cdot {0.9923664122137404}^{7-1}=1965\cdot {0.9923664122137404}^6=1965\cdot 0.9550637025612537=1876.7001755328636$$

$$a_8=a_1·r^{n-1}=1965\cdot {0.9923664122137404}^{8-1}=1965\cdot {0.9923664122137404}^7=1965\cdot 0.9477731399462823=1862.3742199944447$$

$$a_9=a_1·r^{n-1}=1965\cdot {0.9923664122137404}^{9-1}=1965\cdot {0.9923664122137404}^8=1965\cdot 0.9405382304810436=1848.1576228952506$$

$$a_{10}=a_1·r^{n-1}=1965\cdot {0.9923664122137404}^{10-1}=1965\cdot {0.9923664122137404}^9=1965\cdot 0.9333585493323332=1834.0495494380348$$