Mathematics: An arithmetic sequence has t1 = 3, t2 = 10. find tn, sn.

An arithmetic sequence has t1 = 3, t2 = 10. find

20cschultz

10.03.2022

see explanation

Step-by-step explanation:

the n th term of an arithmetic sequence is

$t_{n}$ = $t_{1}$ + (n - 1)d

given $t_{1}$ = 3 and $t_{2}$ = 10, then

$t_{2}$ = 3 + d = 10 ⇒ d = 10 - 3 = 7

$t_{n}$ = 3 + 7(n - 1) = 3 + 7n - 7 = 7n - 4

the sum to n terms of an arithmetic sequence is

$S_{n}$ = $\frac{n}{2}$ [2 $t_{1}$ + (n - 1)d ]

= $\frac{n}{2}$ [(2 × 3) + 7(n - 1) ]

= $\frac{n}{2}$ (6 + 7n - 7 )

= $\frac{n}{2}$ (7n - 1)

= $\frac{7}{2}$ n² - $\frac{1}{2}$ n

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ehsaangaminglegend

21.06.2021

I think the area is 72 sorry if it is wrong I tried

Step-by-step explanation:

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