Let f ( n )= log 1155( n 3) for all n ∈ N, then find the value of f (7)+ f (11)+ f (15).

Question

Let f ( n )= log 1155( n 3) for all n ∈ N, then find the value of f (7)+ f (11)+ f (15). (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

We have, f ( n )=3 log 1155( n ) ∴ f (7)+ f (11)+ f (15)=3( log 1155(7)+ log 1155(11)+ log 1155(15)) =3 log 1155(7 × 11 × 15)=3 log 1155(1155)=3

Q. Let $f (n) = lo g_{1155} (n^{3})$ for all $n \in N$ , then find the value of $f (7) + f (11) + f (15)$ .