This is the basic and conceptual question from Chapter name- Arithmetic Progression
Chapter number- 9
Exercise 9.1
Here we have nth term “an = 2n2 – 3n + 1” of the AP and we are asked to find the first term of it.
CBSE DHANPAT RAI publications
Class:- 10th
Understanding CBSE Mathematics
Question 1 ( viii)
Given:
By putting n = 1, 2, 3, 4, 5 we get first five term of the sequence
a1 = 2 .12 – 3.1 + 1 = 0
a2 = 2. 22 – 3.2 + 1 = 3
a3 = 2.32 – 3.3 + 1 = 10
a4 = 2.42 – 3.4 + 1 = 21
a5 = 2.52 – 3.5 + 1 = 36
∴ The first five terms are 0, 3, 10, 21, 36