Question

Sum of first n term of an arith metic sequence is 3n^2-6n.
Calculate first term and common difference. Write the algebraic form
Find15 th term

Answer 1

Step-by-step explanation:

Sn=3n2-6n

=>S1 or 1st term of the AP= 3(1)^2-6*1=3-6=-3

similarly 2nd term will be 0

then a2-a1=0-(-3)=3

=>cd=3

:.15th term= a+14d

= -3+14*3

=39