Question

What is the n th term of AP whose sum of n term is 2n sqare -3n

Answer 1

Answer:

aₙ=4n-5

Step-by-step explanation:

Given:

Sₙ=2n²-3n

Let's find the first term and common difference a₁ and d:

As, S₁=a₁

• S₁=2*1²-3*1= -1 => a₁ = -1

• S₂=a₁+a₂=a₁+a₁+d=2a₁+d= -2+d

• S₂=2*2²-3*2=2 =>-2+d=2 => d=4

Now, let's find nth term:

• aₙ=a₁+4(n-1)=-1+4n-4=4n-5

• aₙ=4n-5

Answer is 4n-5