CBSE NCERT Solutions Chapter 5 Arithmetic Progressions Exercise 5.2 Question 9
9. If the third and the ninth terms of an AP are 4 and -8 respectively, which term of this AP is zero?
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CBSE NCERT Solutions Chapter 5 Arithmetic Progressions Exercise 5.2 Question 9
9. If the third and the ninth terms of an AP are 4 and -8 respectively, which term of this AP is zero?
In the previous post, we learnt What are arithmetic progressions? In this post, we will learn about nth term of arithmetic progressions. For example, we are given an arithmetic sequence 2, 4, 6, 8, 10 …. Can you find me the value of 54th term? It is very easy to do so with the help of formula
which we will be deriving in this post.
In arithmetic sequences, we have first term equal to
.
Second term
where d is the common difference.
Third term
4th term
Similarly, nth term
For sequence 2, 4, 6, 8, 10 ….
d = 4 – 2 = 2
Can you find 27th term of arithmetic sequence 4, 2, 0, -2, -4, -6….
In this sequence, we have first term
, d = 2-4=-2
Applying formula
, we get
Watch video to have better understanding
Practice questions
…..
Answer 1: -204
Answer 2:
CBSE NCERT Solutions Chapter 5 Arithmetic Progressions Exercise 5.2 Question 6
6. Check whether -150 is a term of the AP:
CBSE NCERT Solutions Chapter 5 Arithmetic Progressions Exercise 5.2 Question 4
4. Which term of the AP: 3, 8, 13, 18, … is 78?
CBSE NCERT Solutions Chapter 5 Arithmetic Progressions Exercise 5.2 Question 3
In the following AP’s find the missing terms:
(i) 2, __ , 26
(ii) __, 13, __, 3
(iii) 5, __, __,
(iv) -4. __, __, __, __, 6
(v) __, 38, __, __, __, -22