সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=355$$ এবং সাধারণ অনুপাত: $$r=0.8$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=355$$

$$a_2=a_1·r^{n-1}=355\cdot {0.8}^{2-1}=355\cdot {0.8}^1=355\cdot 0.8=284$$

$$a_3=a_1·r^{n-1}=355\cdot {0.8}^{3-1}=355\cdot {0.8}^2=355\cdot 0.6400000000000001=227.20000000000005$$

$$a_4=a_1·r^{n-1}=355\cdot {0.8}^{4-1}=355\cdot {0.8}^3=355\cdot 0.5120000000000001=181.76000000000005$$

$$a_5=a_1·r^{n-1}=355\cdot {0.8}^{5-1}=355\cdot {0.8}^4=355\cdot 0.4096000000000001=145.40800000000002$$

$$a_6=a_1·r^{n-1}=355\cdot {0.8}^{6-1}=355\cdot {0.8}^5=355\cdot 0.3276800000000001=116.32640000000004$$

$$a_7=a_1·r^{n-1}=355\cdot {0.8}^{7-1}=355\cdot {0.8}^6=355\cdot 0.2621440000000001=93.06112000000003$$

$$a_8=a_1·r^{n-1}=355\cdot {0.8}^{8-1}=355\cdot {0.8}^7=355\cdot 0.20971520000000007=74.44889600000003$$

$$a_9=a_1·r^{n-1}=355\cdot {0.8}^{9-1}=355\cdot {0.8}^8=355\cdot 0.1677721600000001=59.559116800000034$$

$$a_{10}=a_1·r^{n-1}=355\cdot {0.8}^{10-1}=355\cdot {0.8}^9=355\cdot 0.13421772800000006=47.64729344000002$$