SOLUTION: If the sum of the first n terms of an AP is 4n-n square,what is the first term. What is the first two terms,second term.
Algebra ->
Sequences-and-series
-> SOLUTION: If the sum of the first n terms of an AP is 4n-n square,what is the first term. What is the first two terms,second term.
Log On
Question 972742: If the sum of the first n terms of an AP is 4n-n square,what is the first term. What is the first two terms,second term. Answer by amarjeeth123(570) (Show Source):
You can put this solution on YOUR website! sum of the first n terms of an AP is 4n-n square=n(4-n)=(n/2)(8-2n)=(n/2)[6+(n-1)(-2)]
sum of the first n terms of an AP=(n/2)[2a+(n-1)d]
Comparing both we get a=3 and d=-2
First term a1=3
Second term a2=a+d=3-2=1
(