Question

For the following AP's, write the first term and the common difference.
(i) -5, -1, 3, 7....
(ii) $\frac{1}{3}$,$\frac{5}{3}$,$\frac{9}{3}$,$\frac{13}{3}$,…
(iii) 0.6, 1.7, 2.8, 3.9,…

Answer 1

(i)

-5, -1, 3, 7....

First term = a= -5

Common difference (d) = second term - first term = third term - second term and so on.

Therefore, Common difference (d) = -1-(-5) = -1+5 =4

(ii)

$\frac{1}{3}$, $\frac{5}{3}$, $\frac{9}{3}$, $\frac{13}{3}$....

First term = a= $\frac{1}{3}$

Common difference (d) = second term - first term = third term - second term and so on.

Therefore, Common difference (d) = $\frac{5}{3}$−$\frac{1}{3}$ = $\frac{4}{3}$

(iii)

0.6, 1.7, 2.8, 3.9....

First term = a= 0.6

Common difference (d) = second term - first term = third term - second term and so on.

Therefore, Common difference (d) = 1.7−0.6=1.1