সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=55$$ এবং সাধারণ অনুপাত: $$r=1.4$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=55$$

$$a_2=a_1·r^{n-1}=55\cdot {1.4}^{2-1}=55\cdot {1.4}^1=55\cdot 1.4=77$$

$$a_3=a_1·r^{n-1}=55\cdot {1.4}^{3-1}=55\cdot {1.4}^2=55\cdot 1.9599999999999997=107.79999999999998$$

$$a_4=a_1·r^{n-1}=55\cdot {1.4}^{4-1}=55\cdot {1.4}^3=55\cdot 2.7439999999999993=150.91999999999996$$

$$a_5=a_1·r^{n-1}=55\cdot {1.4}^{5-1}=55\cdot {1.4}^4=55\cdot 3.8415999999999992=211.28799999999995$$

$$a_6=a_1·r^{n-1}=55\cdot {1.4}^{6-1}=55\cdot {1.4}^5=55\cdot 5.378239999999998=295.8031999999999$$

$$a_7=a_1·r^{n-1}=55\cdot {1.4}^{7-1}=55\cdot {1.4}^6=55\cdot 7.529535999999998=414.1244799999999$$

$$a_8=a_1·r^{n-1}=55\cdot {1.4}^{8-1}=55\cdot {1.4}^7=55\cdot 10.541350399999995=579.7742719999998$$

$$a_9=a_1·r^{n-1}=55\cdot {1.4}^{9-1}=55\cdot {1.4}^8=55\cdot 14.757890559999993=811.6839807999996$$

$$a_{10}=a_1·r^{n-1}=55\cdot {1.4}^{10-1}=55\cdot {1.4}^9=55\cdot 20.66104678399999=1136.3575731199994$$