Duration: 8:38

4 views

0

If \( \mathrm{a}_{1}, \mathrm{a}_{2}, \ldots . \mathrm{a}_{\mathrm{n}} \) are in H.P., then the expression \( \mathrm{a}_{1} \mathrm{a}_{2}+\mathrm{a}_{2} \mathrm{a}_{3}+\ldots .+\mathrm{a}_{\mathrm{n}-1} \mathrm{a}_{\mathrm{n}} \) is equal to
(1) \( (n-1)\left(a_{1}-a_{n}\right) \)
(2) \( \mathrm{na}_{1} \mathrm{a}_{\mathrm{n}} \)
(3) \( (n-1) a_{1} a_{n} \)
(4) \( n\left(a_{1}-a_{n}\right) \)
\( \mathrm{P} \)
W
📲PW App Link - https://bit.ly/YTAI_PWAP
🌐PW Website - https://www.pw.live