সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=78$$ এবং সাধারণ অনুপাত: $$r=0.9487179487179487$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=78$$

$$a_2=a_1·r^{n-1}=78\cdot {0.9487179487179487}^{2-1}=78\cdot {0.9487179487179487}^1=78\cdot 0.9487179487179487=74$$

$$a_3=a_1·r^{n-1}=78\cdot {0.9487179487179487}^{3-1}=78\cdot {0.9487179487179487}^2=78\cdot 0.9000657462195923=70.2051282051282$$

$$a_4=a_1·r^{n-1}=78\cdot {0.9487179487179487}^{4-1}=78\cdot {0.9487179487179487}^3=78\cdot 0.8539085284647414=66.60486522024983$$

$$a_5=a_1·r^{n-1}=78\cdot {0.9487179487179487}^{5-1}=78\cdot {0.9487179487179487}^4=78\cdot 0.8101183475178315=63.18923110639086$$

$$a_6=a_1·r^{n-1}=78\cdot {0.9487179487179487}^{6-1}=78\cdot {0.9487179487179487}^5=78\cdot 0.7685738168758914=59.948757716319534$$

$$a_7=a_1·r^{n-1}=78\cdot {0.9487179487179487}^{7-1}=78\cdot {0.9487179487179487}^6=78\cdot 0.72915977498482=56.87446244881596$$

$$a_8=a_1·r^{n-1}=78\cdot {0.9487179487179487}^{8-1}=78\cdot {0.9487179487179487}^7=78\cdot 0.6917669660112394=53.95782334887667$$

$$a_9=a_1·r^{n-1}=78\cdot {0.9487179487179487}^{9-1}=78\cdot {0.9487179487179487}^8=78\cdot 0.6562917369850221=51.19075548483172$$

$$a_{10}=a_1·r^{n-1}=78\cdot {0.9487179487179487}^{10-1}=78\cdot {0.9487179487179487}^9=78\cdot 0.6226357504729696=48.56558853689163$$