Questions
The sum of the infinite series is
detailed solution
Correct option is B
This is clearly not an arithmetico-geometric series,since 1, 4, 9, '16, ... are not in AP. However, their successive differences (4 - 1), (9 - 4), (16 - 9) ,... are in AP.LetS∞=1+43+932+1633+…∞13S∞=13+432+933+…∞On subtraction, we get23S∞=1+33+532+733+…∞⇒13⋅23S∞=13+332+533+…∞ multiplying both sides by 13On subtracting the two series, we get49⋅S∞=1+23+232+233+…∞=1+231+13+132+…∞=1+23×11−13=2∴ S∞=2×94=92Similar Questions
799 666 8865
support@infinitylearn.com
6th Floor, NCC Building, Durgamma Cheruvu Road, Vittal Rao Nagar, HITEC City, Hyderabad, Telangana 500081.
JEE Mock Tests
JEE study guide
JEE Revision Notes
JEE Important Questions
JEE Sample Papers
JEE Previous Year's Papers
NEET previous year’s papers
NEET important questions
NEET sample papers
NEET revision notes
NEET study guide
NEET mock tests