Question

If Sn,the sum of first n terms of an AP is given by An=3n2-4n,find the n th term

Answer 1

Answer:

Step-by-step explanation:

An=3n2-4n

A1=3×(1)2-4×1

A1=3-4=-1

A2=3×(2)2-4×2

A2=24-8=16

A3=3×(3)2-4×3

A3=27-12=15

d=A2-A1

d=16-(-1)

d=17

An=a+(n-1)d

An=-1+(n-)17

An=-1+17n-17

An=17n-18n