Question

Q.5
Let {a} be an arithmetic sequence with first term 77 and common difference -3.
Find the maximum value of .
Find the maximum value of
ak:
k=1​

Answer 1

Answer: ANSWER BELOW :::

Step-by-step explanation:

⭕️Sum of ap = n(2a + (n-1)d) / 2

⭕️For 43, 39, 35, ...

✔️a{First term} = 43

✔️d{Difference i.e a2-a1} = -4

⇒ 252 = n(2 x 43 + (n - 1) x -4) / 2

⇒ 252 = 45n -2n2

⇒ 2n2 - 45n + 252 = 0

⇒ (2n - 21)(n - 12) = 0

⇒ n = 101/2 or 12

✔️101/2th terms don't say accurately which term... so this cannot be an answer......

✔️Thus 12 terms are needed.

PLEASE MARK BRAINLIEST