Ex 5.1, 2
Write first four terms of the A.P. when the first term a and the common difference d are given as follows
(i) a = 10, d = 10
First term = a = 10
Common difference = d = 10
Second term = First term + Common difference
= 10 + 10
= 20
Third term = Second term + Common difference
= 20 + 10
= 30
Fourth term = Third term + Common difference
= 30 + 10
= 40
Hence, first four terms of AP are
10, 20, 30, 40 ……
Ex 5.1, 2
Write first four terms of the A.P. when the first term a and the common difference d are given as follows
(ii) a = −2, d = 0
First term = a = –2
Common difference = d = 0
Second term = First term + Common difference
= –2 + 0
= –2
Third term = Second term + Common difference
= –2 + 0
= –2
Fourth term = Third term + Common difference
= –2 + 0
= –2
Hence , first four term of AP are
– 2, –2, –2, – 2
Ex 5.1, 2
Write first four terms of the A.P. when the first term a and the common difference d are given as follows
(iii) a = 4, d = −3
First term = a = 4
Common difference = –3
Second term = First term + Common difference
= 4 + (–3)
= 4 – 3
= 1
Third term = Second term + Common difference
= 1 + (–3)
= 1 – 3
= –2
Fourth term = third term + common difference
= −2 + (–3)
= –2 – 3
= –5
Hence, first 4 terms of AP are
4, 1, –2, –5
Ex 5.1, 2
Write first four terms of the A.P. when the first term a and the common difference d are given as follows
(iv) a = − 1 d = 1/2
First term = a = –1
Common difference = d = 1/2
Second term = First term + common difference
= – 1 + 1/2
= (−2 + 1)/2
= (−𝟏)/𝟐
Third term = Second term + common difference
= (−1)/2 + 1/2
= 0
Fourth term = third term + common difference
= 0 + 1/2
= (0 + 1)/2
= 𝟏/𝟐
Hence first four terms of AP are
–1, (−𝟏)/𝟐 , 0, 𝟏/𝟐
Ex 5.1, 2
Write first four terms of the A.P. when the first term a and the common difference d are given as follows
(v) a = −1.25, d = −0.25
First term = a = –1.25
Common difference = d = –0.25
Second term = first term + common difference
= –1.25 + (–0.25)
= –1.25 – 0.25
= –1.50
Third term = second term + common difference
= –1.50 + (–0.25)
= –1.50 – 0.25
= –1.75
Fourth term = third term + common difference
= –1.75 + (–0.25)
= –1.75 – 0.25
= –2.00
Hence first 4 terms of AP are
–1.25, –1.50, –1.75, –2.00

Made by

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.