Question

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

Answer 1

(i) $3,1,-1,-3\dots$
Here, first term, $a=3$
Common difference, $d=$ Second term $-$ First term
$d=1-3=-2$
(ii) $-5,-1,3,7\dots$
Here, first term, $a=-5$
Common difference, $d=$ Second term $-$ First term
$d=(-1)-(-5)=-1+5=4$

(iii) $\frac{1}{3},\frac{5}{3},\frac{9}{3},\frac{13}{3}$
Here, first term, $a=\frac{1}{3}$

Common difference, $d=$ Second term $-$ First term

$d=\frac{5}{3}-\frac{1}{3}=\frac{4}{3}$

(iv) $0.6,1.7,2.8,3.9\dots$
Here, first term, $a=0.6$
Common difference, $d=$ Second term $-$ First term
$d=1.7-0.6$
$=1.1$