JEE MATHEMATICS MCQ: SEQUENCE OF SERIES

1 Medium

1 of 1

Application +4 | -1

{a_1},{a_2}, \ldots ,{a_n}

are in HP, then the expression

{a_1}{a_2} + {a_2}{a_3} + .. + {a_{n - 1}}{a_n}

is equal to

View answer and explanation

Correct option: C

\left( {n - 1} \right){a_1}{a_n}

Option C (

\left( {n - 1} \right){a_1}{a_n}

) is correct because, using the properties of Harmonic Progression (HP) and manipulating the terms, the expression simplifies to this result.

More Questions from SEQUENCE OF SERIES

Practice All Chapter MCQs →

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

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

A-(B \cap C)

(B \cup C)-A

a,b,c

a,x,b

b,y,c

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

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

y

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

y=x-2

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

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

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

A P

a, b

G P

a, b, c

\frac{3}{4}