সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=550$$ এবং সাধারণ অনুপাত: $$r=0.8$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=550$$

$$a_2=a_1·r^{n-1}=550\cdot {0.8}^{2-1}=550\cdot {0.8}^1=550\cdot 0.8=440$$

$$a_3=a_1·r^{n-1}=550\cdot {0.8}^{3-1}=550\cdot {0.8}^2=550\cdot 0.6400000000000001=352.00000000000006$$

$$a_4=a_1·r^{n-1}=550\cdot {0.8}^{4-1}=550\cdot {0.8}^3=550\cdot 0.5120000000000001=281.6000000000001$$

$$a_5=a_1·r^{n-1}=550\cdot {0.8}^{5-1}=550\cdot {0.8}^4=550\cdot 0.4096000000000001=225.28000000000003$$

$$a_6=a_1·r^{n-1}=550\cdot {0.8}^{6-1}=550\cdot {0.8}^5=550\cdot 0.3276800000000001=180.22400000000005$$

$$a_7=a_1·r^{n-1}=550\cdot {0.8}^{7-1}=550\cdot {0.8}^6=550\cdot 0.2621440000000001=144.17920000000007$$

$$a_8=a_1·r^{n-1}=550\cdot {0.8}^{8-1}=550\cdot {0.8}^7=550\cdot 0.20971520000000007=115.34336000000005$$

$$a_9=a_1·r^{n-1}=550\cdot {0.8}^{9-1}=550\cdot {0.8}^8=550\cdot 0.1677721600000001=92.27468800000005$$

$$a_{10}=a_1·r^{n-1}=550\cdot {0.8}^{10-1}=550\cdot {0.8}^9=550\cdot 0.13421772800000006=73.81975040000003$$