সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=86$$ এবং সাধারণ অনুপাত: $$r=0.8604651162790697$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=86$$

$$a_2=a_1·r^{n-1}=86\cdot {0.8604651162790697}^{2-1}=86\cdot {0.8604651162790697}^1=86\cdot 0.8604651162790697=74$$

$$a_3=a_1·r^{n-1}=86\cdot {0.8604651162790697}^{3-1}=86\cdot {0.8604651162790697}^2=86\cdot 0.740400216333153=63.67441860465116$$

$$a_4=a_1·r^{n-1}=86\cdot {0.8604651162790697}^{4-1}=86\cdot {0.8604651162790697}^3=86\cdot 0.6370885582401549=54.78961600865332$$

$$a_5=a_1·r^{n-1}=86\cdot {0.8604651162790697}^{5-1}=86\cdot {0.8604651162790697}^4=86\cdot 0.5481924803461797=47.14455330977146$$

$$a_6=a_1·r^{n-1}=86\cdot {0.8604651162790697}^{6-1}=86\cdot {0.8604651162790697}^5=86\cdot 0.47170050634438726=40.566243545617304$$

$$a_7=a_1·r^{n-1}=86\cdot {0.8604651162790697}^{7-1}=86\cdot {0.8604651162790697}^6=86\cdot 0.4058818310405192=34.90583746948465$$

$$a_8=a_1·r^{n-1}=86\cdot {0.8604651162790697}^{8-1}=86\cdot {0.8604651162790697}^7=86\cdot 0.3492471569418421=30.03525549699842$$

$$a_9=a_1·r^{n-1}=86\cdot {0.8604651162790697}^{9-1}=86\cdot {0.8604651162790697}^8=86\cdot 0.3005149955080967=25.844289613696315$$

$$a_{10}=a_1·r^{n-1}=86\cdot {0.8604651162790697}^{10-1}=86\cdot {0.8604651162790697}^9=86\cdot 0.25858267055347856=22.238109667599154$$