সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=60$$ এবং সাধারণ অনুপাত: $$r=1.4$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=60$$

$$a_2=a_1·r^{n-1}=60\cdot {1.4}^{2-1}=60\cdot {1.4}^1=60\cdot 1.4=84$$

$$a_3=a_1·r^{n-1}=60\cdot {1.4}^{3-1}=60\cdot {1.4}^2=60\cdot 1.9599999999999997=117.59999999999998$$

$$a_4=a_1·r^{n-1}=60\cdot {1.4}^{4-1}=60\cdot {1.4}^3=60\cdot 2.7439999999999993=164.63999999999996$$

$$a_5=a_1·r^{n-1}=60\cdot {1.4}^{5-1}=60\cdot {1.4}^4=60\cdot 3.8415999999999992=230.49599999999995$$

$$a_6=a_1·r^{n-1}=60\cdot {1.4}^{6-1}=60\cdot {1.4}^5=60\cdot 5.378239999999998=322.69439999999986$$

$$a_7=a_1·r^{n-1}=60\cdot {1.4}^{7-1}=60\cdot {1.4}^6=60\cdot 7.529535999999998=451.7721599999999$$

$$a_8=a_1·r^{n-1}=60\cdot {1.4}^{8-1}=60\cdot {1.4}^7=60\cdot 10.541350399999995=632.4810239999997$$

$$a_9=a_1·r^{n-1}=60\cdot {1.4}^{9-1}=60\cdot {1.4}^8=60\cdot 14.757890559999993=885.4734335999996$$

$$a_{10}=a_1·r^{n-1}=60\cdot {1.4}^{10-1}=60\cdot {1.4}^9=60\cdot 20.66104678399999=1239.6628070399993$$