If and f(1) = 1, f(p + q) = f(p). f(q)p, q ∈ R then,
Since,
Also, f(p + q) = f(p). f(q) ∀ p, q ∈ R …. (1)
Given, f(1) = 1
From (1),
f(1 + 1) = f(1). f(1)
⇒ f(2) =12 = 1 ………. (2)
From (2), f(2 + 1) = f(2) . f(1)
⇒ f(3) = 12 .1 = 13 = 1
Now, given expression