সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=35$$ এবং সাধারণ অনুপাত: $$r=0.8$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=35$$

$$a_2=a_1·r^{n-1}=35\cdot {0.8}^{2-1}=35\cdot {0.8}^1=35\cdot 0.8=28$$

$$a_3=a_1·r^{n-1}=35\cdot {0.8}^{3-1}=35\cdot {0.8}^2=35\cdot 0.6400000000000001=22.400000000000006$$

$$a_4=a_1·r^{n-1}=35\cdot {0.8}^{4-1}=35\cdot {0.8}^3=35\cdot 0.5120000000000001=17.920000000000005$$

$$a_5=a_1·r^{n-1}=35\cdot {0.8}^{5-1}=35\cdot {0.8}^4=35\cdot 0.4096000000000001=14.336000000000002$$

$$a_6=a_1·r^{n-1}=35\cdot {0.8}^{6-1}=35\cdot {0.8}^5=35\cdot 0.3276800000000001=11.468800000000003$$

$$a_7=a_1·r^{n-1}=35\cdot {0.8}^{7-1}=35\cdot {0.8}^6=35\cdot 0.2621440000000001=9.175040000000003$$

$$a_8=a_1·r^{n-1}=35\cdot {0.8}^{8-1}=35\cdot {0.8}^7=35\cdot 0.20971520000000007=7.3400320000000026$$

$$a_9=a_1·r^{n-1}=35\cdot {0.8}^{9-1}=35\cdot {0.8}^8=35\cdot 0.1677721600000001=5.872025600000003$$

$$a_{10}=a_1·r^{n-1}=35\cdot {0.8}^{10-1}=35\cdot {0.8}^9=35\cdot 0.13421772800000006=4.697620480000002$$