Find the second term and nth term of an A.P. whose 6th term is 12 and the 8th term is 22.
a6= a + 5d
12= a + 5d …(i)
a8= a + 7d
22= a + 7d …(ii)
Subtracting (i) from (ii), we get,
10= 2d
d= 5
from (i)
12 = a + 5(5)
12= a + 25
a= -13
a2= a +d
=-13 +5
=-8
an= a + (n-1)d
= -13 + (n-1)5
=-18 +5n