সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=72$$ এবং সাধারণ অনুপাত: $$r=0.8888888888888888$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=72$$

$$a_2=a_1·r^{n-1}=72\cdot {0.8888888888888888}^{2-1}=72\cdot {0.8888888888888888}^1=72\cdot 0.8888888888888888=64$$

$$a_3=a_1·r^{n-1}=72\cdot {0.8888888888888888}^{3-1}=72\cdot {0.8888888888888888}^2=72\cdot 0.7901234567901234=56.888888888888886$$

$$a_4=a_1·r^{n-1}=72\cdot {0.8888888888888888}^{4-1}=72\cdot {0.8888888888888888}^3=72\cdot 0.7023319615912207=50.56790123456789$$

$$a_5=a_1·r^{n-1}=72\cdot {0.8888888888888888}^{5-1}=72\cdot {0.8888888888888888}^4=72\cdot 0.624295076969974=44.949245541838124$$

$$a_6=a_1·r^{n-1}=72\cdot {0.8888888888888888}^{6-1}=72\cdot {0.8888888888888888}^5=72\cdot 0.5549289573066435=39.95488492607833$$

$$a_7=a_1·r^{n-1}=72\cdot {0.8888888888888888}^{7-1}=72\cdot {0.8888888888888888}^6=72\cdot 0.49327018427257197=35.51545326762518$$

$$a_8=a_1·r^{n-1}=72\cdot {0.8888888888888888}^{8-1}=72\cdot {0.8888888888888888}^7=72\cdot 0.43846238602006393=31.569291793444602$$

$$a_9=a_1·r^{n-1}=72\cdot {0.8888888888888888}^{9-1}=72\cdot {0.8888888888888888}^8=72\cdot 0.3897443431289457=28.061592705284088$$

$$a_{10}=a_1·r^{n-1}=72\cdot {0.8888888888888888}^{10-1}=72\cdot {0.8888888888888888}^9=72\cdot 0.34643941611461837=24.943637960252524$$