Write the first five terms of the sequences whose $n^{t h}$ term is $a_{n}=n(n+2)$

Vedclass pdf generator app on play store
Vedclass iOS app on app store

$a_{n}=n(n+2)$

Substituting $n=1,2,3,4$ and $5,$ we obtain

$a_{1}=1(1+2)=3$

$a_{2}=2(2+2)=8$

$a_{3}=3(3+2)=15$

$a_{4}=4(4+2)=24$

$a_{5}=5(5+2)=35$

Therefore, the required terms are $3,8,15,24$ and $35 .$

Similar Questions

Let $S_n$ be the sum to n-terms of an arithmetic progression $3,7,11, \ldots \ldots$. . If $40<\left(\frac{6}{\mathrm{n}(\mathrm{n}+1)} \sum_{\mathrm{k}=1}^{\mathrm{n}} \mathrm{S}_{\mathrm{k}}\right)<42$, then $\mathrm{n}$ equals

  • [JEE MAIN 2024]

The number of terms in an $A .P.$ is even ; the sum of the odd terms in it is $24$ and that the even terms is $30$. If the last term exceeds the first term by $10\frac{1}{2}$ , then the number of terms in the $A.P.$ is

  • [JEE MAIN 2014]

A manufacturer reckons that the value of a machine, which costs him $Rs.$ $15625$ will depreciate each year by $20 \% .$ Find the estimated value at the end of $5$ years.

Jairam purchased a house in Rs. $15000$ and paid Rs. $5000$ at once. Rest money he promised to pay in annual installment of Rs. $1000$ with $10\%$ per annum interest. How much money is to be paid by Jairam $\mathrm{Rs.}$ ...................

If $a_1, a_2, a_3 …………$ an are in $A.P$ and $a_1 + a_4 + a_7 + …………… + a_{16} = 114$, then $a_1 + a_6 + a_{11} + a_{16}$ is equal to

  • [JEE MAIN 2019]