সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=69$$ এবং সাধারণ অনুপাত: $$r=0.8695652173913043$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=69$$

$$a_2=a_1·r^{n-1}=69\cdot {0.8695652173913043}^{2-1}=69\cdot {0.8695652173913043}^1=69\cdot 0.8695652173913043=60$$

$$a_3=a_1·r^{n-1}=69\cdot {0.8695652173913043}^{3-1}=69\cdot {0.8695652173913043}^2=69\cdot 0.7561436672967864=52.17391304347826$$

$$a_4=a_1·r^{n-1}=69\cdot {0.8695652173913043}^{4-1}=69\cdot {0.8695652173913043}^3=69\cdot 0.6575162324319881=45.368620037807176$$

$$a_5=a_1·r^{n-1}=69\cdot {0.8695652173913043}^{5-1}=69\cdot {0.8695652173913043}^4=69\cdot 0.5717532455930331=39.45097394591928$$

$$a_6=a_1·r^{n-1}=69\cdot {0.8695652173913043}^{6-1}=69\cdot {0.8695652173913043}^5=69\cdot 0.49717673529828965=34.305194735581985$$

$$a_7=a_1·r^{n-1}=69\cdot {0.8695652173913043}^{7-1}=69\cdot {0.8695652173913043}^6=69\cdot 0.43232759591155623=29.83060411789738$$

$$a_8=a_1·r^{n-1}=69\cdot {0.8695652173913043}^{8-1}=69\cdot {0.8695652173913043}^7=69\cdot 0.37593703992309235=25.939655754693373$$

$$a_9=a_1·r^{n-1}=69\cdot {0.8695652173913043}^{9-1}=69\cdot {0.8695652173913043}^8=69\cdot 0.32690177384616725=22.55622239538554$$

$$a_{10}=a_1·r^{n-1}=69\cdot {0.8695652173913043}^{10-1}=69\cdot {0.8695652173913043}^9=69\cdot 0.2842624120401454=19.614106430770033$$