解答 - 几何数列

要找到系列的通用形式，将第一项：$$a=29$$ 和公比：$$r=27.586206896551722$$ 插入几何级数的公式：

$$a_1=29$$

$$a_2=a_1·r^{n-1}=29\cdot {27.586206896551722}^{2-1}=29\cdot {27.586206896551722}^1=29\cdot 27.586206896551722=800$$

$$a_3=a_1·r^{n-1}=29\cdot {27.586206896551722}^{3-1}=29\cdot {27.586206896551722}^2=29\cdot 760.9988109393578=22068.965517241377$$

$$a_4=a_1·r^{n-1}=29\cdot {27.586206896551722}^{4-1}=29\cdot {27.586206896551722}^3=29\cdot 20993.070646602973=608799.0487514862$$

$$a_5=a_1·r^{n-1}=29\cdot {27.586206896551722}^{5-1}=29\cdot {27.586206896551722}^4=29\cdot 579119.1902511164=16794456.517282374$$

$$a_6=a_1·r^{n-1}=29\cdot {27.586206896551722}^{6-1}=29\cdot {27.586206896551722}^5=29\cdot 15975701.800030798=463295352.20089316$$

$$a_7=a_1·r^{n-1}=29\cdot {27.586206896551722}^{7-1}=29\cdot {27.586206896551722}^6=29\cdot 440709015.1732634=12780561440.024637$$

$$a_8=a_1·r^{n-1}=29\cdot {27.586206896551722}^{8-1}=29\cdot {27.586206896551722}^7=29\cdot 12157490073.745195=352567212138.61066$$

$$a_9=a_1·r^{n-1}=29\cdot {27.586206896551722}^{9-1}=29\cdot {27.586206896551722}^8=29\cdot 335379036517.1088=9725992058996.156$$

$$a_{10}=a_1·r^{n-1}=29\cdot {27.586206896551722}^{10-1}=29\cdot {27.586206896551722}^9=29\cdot 9251835490127.139=268303229213687.03$$