(4) Find the 12th term of the A.P √2 , 3 √2 , 5 √2 , …………

Solution :

First term (a)  = √2

Common difference (d)  = 3 √2 - √2 = 2 √2

n = 12

General term of an A.P

tn =  a + (n - 1) d

t₁₂ =  √2 + (12 - 1) (2√2)

=  √2 + 11 (2√2)

=  √2 + 22 √2

=  23 √2

Hence, 12th of A.P is 23 √2