Question

the sum of an terms of an AP is 2n²-n-1. Find an!​

Answer 1

sum of first 1 terms is 0

let a be the first term common difference=d

sum of first 2 terms is 5

so we get 2 equations

a=0

a+d=5

so d=5

and nth term=a+(n-1)d

=0+(n-1)5

=5n-5