44. If the nth term of an AP is (2n + 1), find the sum of first n terms of the AP.
Chapter name :- Arithmetic Progressions
Answers
Answered by
1
Answer:
2n+1=44
2n=44-1
2n=43
n=43/2
n=21.5
Answered by
2
Answer:
n th term l = 2n+1 (given)-----(1)
If we put n=1,we get first term of an A.P.
Then first term a=2(1)+1
a=3;-----(2)
Now we can find out sum of first n terms using this formula
sum of n terms of an A.P.=n/2(a+l)
(Here a is first term of an A.P. and l is last or nth term of A.P.)
Values of a and l putting in the equation (3) from (2) and (1)
Sum of first n terms of an A.P.=n/2(3+2n+1)
=> n/2(2n+4)
=> n(n+2)
Step-by-step explanation:
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