JEE MATHEMATICS MCQ: SEQUENCE OF SERIES

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Application +4 | -1

the sum of

n

terms of the infinite series

1 \cdot {3^2} + 2 \cdot {5^2} + 3 \cdot {7^2} + ...\infty

View answer and explanation

Correct option: A

\frac{n}{6}\left( {n + 1} \right)\left( {6{n^2} + 14n + 7} \right)

Option A (

\frac{n}{6}

\left( {n + 1} \right)\left( {6{n²} + 14n + 7} \right)) is correct because it is the correct formula for the sum of the given arithmetico-geometric series.

More Questions from SEQUENCE OF SERIES

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Given the sets

A=\{1,2,3\}, B=\{3,4\}, C=\{4,5,6\}

, then find the following
(i)

{A} \cup({B} \cap {C})

(ii)

A-(B \cap C)

(iii)

(B \cup C)-A

a,b,c

are in A.P.;

a,x,b

are in G.P. and

b,y,c

are in G.P., then

{x^2},{b^2},{y^2}

are in Suppose

P(x)=1-x+x^2-x^3+\ldots+x^{2012}

is expressed as a polynomial in

y

, as

Q(y)=a_0+a_1 y+\ldots+a_{2012} y^{2012}

where

y=x-2

, then

\sum\limits_{{i=0}}^{2012} a_i

equals If

\log \left(\frac{5 c}{a}\right), \log \left(\frac{3 b}{5 c}\right)

and

\log \left(\frac{a}{3 b}\right)

are in

A P

, where

a, b

and c are in

G P

, then

a, b, c

are the lengths of sides of If the sum of three numbers in G.P. is 63 and the product of the first and the second term is

\frac{3}{4}

of the third term, then the numbers are If the lengths of sides of a right angled triangle are in A.P., then their ratio is