IF a_(1,) a_2 ,.....,a_(n−1) ,a_n are in AP then prove that
1/a_1 .a_n + 1/a_2 .a_(n−1) + 1/a_3 .a_(n−2) +...+1/a_n .a_1 =
2/a_1 +a_(n ) [1/a_(1 ) +1/a_2 +....+1/a_n ]
If N is perfect nth power, prove that
n ∣ (d(N)−1)
[Where d(N) denotes number
of divisors of N]
Also show by an example that its
vice versa is not necessarily correct.