Question

if the sumif the sum of the first n terms of an ap is 4n-n²and what is the first term S1? what is the sum of the first two terms what is the second term similarly find the third term , the 10th term in the nth term​

Answer 1

Answer:

Step-by-step explanation:

Sₙ = 4n² - n

Sₙ₋₁ = 4(n-1)²-(n-1)

=4(n²-2n+1)-n+1

=4n²-8n+4-n+1

=4n²-9n+5

∴tₙ=Sₙ-Sₙ₋₁

=4n²-n-4n²+9n-5

=8n-5

Now replace n with the required term no.