সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=60$$ এবং সাধারণ অনুপাত: $$r=3.5$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=60$$

$$a_2=a_1·r^{n-1}=60\cdot {3.5}^{2-1}=60\cdot {3.5}^1=60\cdot 3.5=210$$

$$a_3=a_1·r^{n-1}=60\cdot {3.5}^{3-1}=60\cdot {3.5}^2=60\cdot 12.25=735$$

$$a_4=a_1·r^{n-1}=60\cdot {3.5}^{4-1}=60\cdot {3.5}^3=60\cdot 42.875=2572.5$$

$$a_5=a_1·r^{n-1}=60\cdot {3.5}^{5-1}=60\cdot {3.5}^4=60\cdot 150.0625=9003.75$$

$$a_6=a_1·r^{n-1}=60\cdot {3.5}^{6-1}=60\cdot {3.5}^5=60\cdot 525.21875=31513.125$$

$$a_7=a_1·r^{n-1}=60\cdot {3.5}^{7-1}=60\cdot {3.5}^6=60\cdot 1838.265625=110295.9375$$

$$a_8=a_1·r^{n-1}=60\cdot {3.5}^{8-1}=60\cdot {3.5}^7=60\cdot 6433.9296875=386035.78125$$

$$a_9=a_1·r^{n-1}=60\cdot {3.5}^{9-1}=60\cdot {3.5}^8=60\cdot 22518.75390625=1351125.234375$$

$$a_{10}=a_1·r^{n-1}=60\cdot {3.5}^{10-1}=60\cdot {3.5}^9=60\cdot 78815.638671875=4728938.3203125$$