Math, asked by gmkbiochem2021, 29 days ago

4.The sum to 'n' terms of an arithmetic sequence is 4n² - 2n. i) Write the first term of the sequence.​

Answers

Answered by bhagyalakshmi9595
1

Answer:

Given that

the sum of n terms of an arithmetic sequence

Sₙ = 4n² + 3n

So, nᵗʰ term of the sequence

Tₙ = Sₙ — Sₙ_₁

= (4n² + 3n) — {4(n — 1)² + 3(n — 1)}

= 4n² + 3n — {4(n² + 1 — 2n) + 3(n — 1)}

= 4n² + 3n — {4n² + 4 — 8n + 3n — 3}

= 4n² + 3n — 4n² — 4 + 8n — 3n + 3

= 8n — 1

So first term,

T₁ = 8(1) — 1 = 8 — 1 = 7

Hope it will help you

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